Chapter 16: Giving Birth: McKinney

Breech Presentation

A breech presentation occurs when the fetal buttocks or feet enter the pelvis first. They are common, occurring in approximately about 3% of births (Cunningham et al., 2010; Tarsa & Moore, 2010). Breech presentations are associated with several disadvantages: •The buttocks are not smooth and firm like the head and are less effective at dilating the cervix. •The fetal head is the last part to be born. By the time the fetal head is deep in the pelvis, the umbilical cord is subject to compression between the baby's head and the maternal pelvis. •Because the umbilical cord can be compressed after the fetal chest is born, the head must be delivered quickly to allow the infant to breathe. This necessary speed does not permit gradual molding of the fetal head as it passes through the pelvis. The breech presentation has three variations, depending on the relationship of the legs to the body (Figure 16-9).

Individual and Cultural Values

A family's culture affects its members' views of birth and the practices that surround it. Culture shapes the values that people hold, their expectations of the birth experience, and their responses to birth. A woman's culture gives her cues about how she should behave and react to labor and how she should interact with her newborn. If the woman, her family, and caregivers have similar views, little conflict in their values and expectations is likely. However, if these individuals hold markedly different views, they may be confused because each expects something different of the other. Knowledge of the values and practices of cultural groups that the nurse encounters provides a framework to assess and care for the woman and her family, but within a culture, people are individuals. The nurse must assess the personal expectations and birth-related values of each woman and her family within this general framework. Aspects of cultural assessment for the intrapartum period might include: •How long has the family been in the area? Are they recent immigrants, or have their relatives and friends lived in the area for generations? •What is the family's primary language? Do the woman and her family speak the same language or does only one of them speak the dominant language? Is the dominant language not spoken by either the woman or her support person? Are they comfortable communicating in the nurse's language if the two are different? If an interpreter is needed, are there people the family considers unacceptable (e.g., a male or a member of certain religious groups)? How does a hearing-impaired woman communicate with people who hear? •Who is the decision-maker in the family, or who must be consulted about important decisions? •Will another relative (such as a grandmother) assume primary care for the infant? •Is a caregiver of the same gender and cultural group essential? •Who is the woman's primary support person for labor? What is that person's role? How extensively will that support person interact with the laboring woman? Who will be present at birth? •What are the woman's feelings about touch? Is she comfortable telling the nurse when she does or does not welcome touch? •Are specific symbols, practices, or ceremonies used during the birth period? Who will conduct any ceremonies?

Establishing a Therapeutic Relationship Making the Family Feel Welcome

A family's first impression influences how family members feel about the quality of the birth experience. Even if the unit is busy, the nurse should communicate interest, friendliness, caring, and competence. Families understand if the nurse is busy; they do not understand rudeness or insensitivity to their needs. Nurses frequently encounter women who speak a language other than English. Arranging for a culturally acceptable interpreter who is fluent in the woman's language makes the woman and family feel more welcome and promotes safety because it enhances understanding among the woman, her family, and the nurse. Telephone interpreters may be available for languages encountered in a facility. Arrangements may be needed for sign language interpreters or other means for language translation between the hearing and the hearing impaired. See the National Institute on Deafness and Other Communication Disorders website at www.nidcd.nih.gov for more information.

Friedman curve

A labor curve may be used to identify whether a woman's cervical dilation is progressing at the expected rate. Typical labor curves for a multiparous and a nulliparous woman are illustrated for comparison of patterns.

CRITICAL THINKING EXERCISE 16-1

A man phones you as you are working in the birth unit of your hospital one night. He says, "My wife's baby is almost due. She's been having some contractions off and on all day, and they are keeping her awake now. Should we come to the hospital?" 1.Do you need any other information? If so, what information do you need?" 2.What should you tell her about her symptoms? What advice should you give her?

Assessments at the Time of Admission

A paper or computer-based record of prenatal care is sent to the center where the woman plans to give birth before her due date and verified or updated on admission. Although prenatal records are becoming more accessible through computer networks, many factors may require paper records of care. Women who have not had prenatal care need a more extensive assessment by the nurse and physician or nurse-midwife. Table 16-2 lists intrapartum assessments, usual findings, significant findings, and appropriate nursing actions.

Fetal Head Diameters

Although most fetuses enter the pelvis in the cephalic presentation, several variations are possible. The major transverse diameter of the fetal head is the biparietal, measured between the two parietal bones and averages 9.5 cm in a term fetus. The anteroposterior diameter of the head varies with the degree of flexion. In the most favorable situation, the head becomes fully flexed during labor and the anteroposterior diameter is the suboccipitobregmatic, averaging 9.5 cm. See Figure 16-5, B, on p. 324, for anteroposterior head diameters in different degrees of head flexion and extension.

Dilation

As the cervix is pulled upward and the fetus is pushed downward, the cervix dilates. Dilation is expressed in centimeters, with approximately 10 cm being full dilation, large enough to allow passage of the average-size term fetus. The action during effacement and dilation can be likened to pushing a tennis ball out the cuff of a sock.

Maternal Vital Signs

Assess maternal vital signs primarily for signs of hypertension or infection. Hypertension during pregnancy is defined as a sustained blood pressure increase to 140 mm Hg systolic or higher or 90 mm Hg diastolic or higher (American Academy of Pediatrics [AAP] & American College of Obstetricians and Gynecologists [ACOG], 2007; Castro, 2010). A temperature of 38° C (100.4° F) or higher suggests infection.

Maternal Pushing Efforts

At some point during the second stage of labor (full cervical dilation through birth of the baby), the woman adds her voluntary pushing efforts to the force of uterine contractions to propel the fetus through the pelvis.

Pelvic divisions and measurements

Be sure to go over 16-4; very important

EXTENSION

Because the true pelvis is shaped like a curved cylinder, the fetal head is directed posteriorly toward the rectum as it begins its descent. To negotiate the curve of the pelvis, the fetal head must change from an attitude of flexion to one of extension. While still in flexion, the fetal head meets resistance from the tissues of the pelvic floor. At the same time, the fetal neck stops under the symphysis, which acts as a pivot. The combination of resistance from the pelvic floor and the pivoting action of the symphysis causes the fetal head to swing anteriorly, or extend, with each maternal pushing effort. The head is born in extension, with the occiput sliding under the symphysis and the face directed toward the rectum. The fetal brow, nose, and chin slide over the perineum as the head is born.

Fetal Pulmonary System

Before birth, the fetal lungs are filled with fluid to allow normal development of the airways. This fluid must be cleared to allow air breathing. As term approaches, production of fetal lung fluid decreases and its absorption increases. Labor intensifies the absorption of lung fluid. Some fluid is expelled from the upper airways as the fetal head and thorax are compressed during passage through the birth canal. The remaining fluid is absorbed into the newborn's pulmonary and lymphatic circulations after birth. Chapter 21 contains added information about newborn transition.

Effacement

Before labor the cervix is a cylindric structure, about 2 cm long, at the lower end of the uterus. Labor contractions push the fetus downward against the cervix as they pull the cervix upward. The cervix becomes shorter and thinner as it is drawn over the fetus and amniotic sac (Figure 16-3). The cervix merges with the thinning lower uterus rather than remaining a distinct cylindric structure. Effacement is estimated as a percentage of the amount the cervix has thinned, so that a fully thinned cervix is 100% effaced. Effacement also may be recorded as cervical length, estimated in centimeters during vaginal examination.

Premonitory Signs

Before spontaneous labor begins, women usually notice one or more of the following premonitory, or warning, signs that labor is near: •Braxton Hicks contractions, irregular mild contractions which occur throughout pregnancy increase in frequency and are sometimes painful. They may become regular at times, only to decrease spontaneously. •Lightening ("dropping") occurs as the fetus descends toward the pelvic inlet. Lightening is most noticeable in nulliparas, occurring about 2 to 3 weeks before the onset of labor. •Increased clear and nonirritating vaginal secretions occur as fetal pressure causes congestion of the vaginal mucosa. •"Bloody show," a mixture of thick mucus and pink or dark brown blood, may occur as the cervix begins to soften, dilate, and efface slightly ("ripening"). •An energy spurt ("nesting"). •A small weight loss of 2.2 kg to 6.6 kg (1 to 3 lb) may occur because changing levels of estrogen and progesterone cause excretion of some of the extra fluid that accumulates during pregnancy.

Assigning a Primary Nurse

Birth, even if induced, does not fit neatly into nursing schedules. Thus having one nurse give care during all of labor is unrealistic. The number of different caregivers should, however, be limited as much as possible. The woman should know who each caregiver is and what to expect from each.

Cardiovascular System

During each uterine contraction, blood flow to the placenta gradually decreases, causing a relative increase in the woman's blood volume. This temporary change increases her blood pressure slightly and slows her pulse. Therefore the mother's vital signs are best assessed during the interval between contractions. Although it is more likely to occur during the antepartum period because the fetus has not yet started to descend, supine hypotension also may occur during labor if the mother lies on her back (see Figure 13-4). The mother should be encouraged to rest in positions other than the supine to promote blood return to her heart and therefore enhance blood flow to the placenta and promote fetal oxygenation.

Bones, Sutures, and Fontanels

Bones, Sutures, and Fontanels The bones of the fetal head involved in birth are the two frontal bones on the forehead, the two parietal bones at the crown of the head, and the occipital bone at the back of the head (Figure 16-5, p. 324). The five major bones are not fused but are connected by sutures composed of strong but flexible fibrous tissue. The fontanels are wider spaces at the intersections of the sutures. The anterior fontanel is diamond shaped and formed by the intersection of four sutures: the two coronal, the frontal, and the sagittal, which connect the two frontal and the two parietal bones. The posterior fontanel has a triangular shape formed by the intersection of three sutures, one sagittal and two lambdoid, which connect the two parietal bones and the occipital bone. The posterior fontanel is very small, often more like a slight depression in the skull. The sutures and fontanels allow the bones to move slightly, changing the shape of the fetal head so that it can adapt to the size and shape of the pelvis by molding. The sutures and the different shapes of the fontanels provide landmarks to determine fetal position and head flexion during vaginal examination.

Synopsis of chapter

Care of the woman and her family during labor and birth is a rewarding field of nursing. The birth of a baby is more than a physical event; it has deep personal and social significance for the family. Family roles and relationships are forever altered by this event. (Be sure to refer to this chapter frequently for detailed pictures and modules)

Multigravida vs Primigravida Cervical changes

Cervical dilation and effacement. During labor, the multigravida's cervix remains thicker than that of the primigravida. Refer to FIG 16-3

First Stage of Labor

Cervical effacement and dilation occur in the first stage of labor, or stage of dilation. It begins with the onset of true labor contractions and ends with complete dilation (10 cm) and effacement (100%) of the cervix. The first stage of labor is the longest for both nulliparous and parous women. Labor progress may be plotted on a graph, often called a Friedman curve (Figure 16-13, p. 333). However, the Friedman curve cannot be the only measure of normal progress with today's technology. Current measures of maternal and fetal well-being, such as fetal monitoring, provide added information about whether a longer labor duration should be ended or allowed to continue. First-stage labor differs from the other stages because it has three phases: latent (early), active, and transition. Each phase is characterized by typical maternal behaviors. These behaviors vary with the woman's preparation, use of coping skills, and analgesia.

Birth as an Experience

Childbirth is a physical and emotional experience. It is also an irrevocable event that changes a woman and her family forever. Families describe the births of children as they describe other pivotal events in life: marriages, anniversaries, religious events, and even deaths. Women often have specific expectations about the experience of childbirth. The more realistic a woman's expectations about the birth are, the more likely she is to have a positive experience. Nursing measures that increase a sense of control and mastery during birth help families perceive the birth as a positive event. Nursing measures to empower families include teaching them about their choices in childbirth in an unbiased way and supporting the choices they make.

Issues for New Nurses

Common issues face new nurses and nursing students when caring for families during birth. Such as: Pain associated with birth, inexperience or negative experiences, unpredictability, Intimacy, Physiologic effects of the birth process, maternal response

PATIENT-CENTERED TEACHING: How to Know Whether Labor Is "Real" True labor differs from false labor in three categories. FALSE LABOR TRUE LABOR

Contractions Inconsistent in frequency, duration, and intensity. A consistent pattern of increasing frequency, duration, and intensity usually develops. A change in activity, such as walking, does not alter contractions, or activity may decrease them. Walking tends to increase contractions. Discomfort Felt in the abdomen and groin. Begins in lower back and gradually sweeps around to the lower abdomen like a girdle. May be more annoying than truly painful. Back pain may persist in some women. Early labor often feels like menstrual cramps. Cervix No significant change in effacement or dilation of the cervix after an observation period of 1 to 2 hours. Effacement and/or dilation of cervix occurs. Progressive effacement and dilation of cervix are most important characteristics. The mechanisms of labor are different in presentations other than the vertex, but the reason is the same: effective use of available space in the maternal pelvis.

Respecting Cultural Values

Cultural beliefs and practices give structure and meaning to the birth experience. The nurse should incorporate a family's cultural practices into care as much as possible.

DESCENT, ENGAGEMENT, AND FLEXION

Descent of the fetus is a mechanism of labor that accompanies all the others. Without descent, none of the mechanisms will occur.

EVIDENCE-BASED PRACTICE

Does delayed pushing versus immediate pushing during a woman's second stage have any physical advantages for her? What about her newborn? Two nursing research articles provide evidence that delaying pushing when a nullipara reaches second stage shortened the duration of pushing compared to the nulliparas in the immediate pushing group. However the total length of second stage was longer in the delayed pushing group in each study, an expected finding. Primary outcome measures in both studies were the length of pushing during second stage, total length of second stage, and maternal fatigue. Kelly, Johnson, Lee, et al. (2010) conducted a randomized clinical trial (RCT) for 44 nulliparas: immediate pushing for 28; delayed pushing for 16. Consent was obtained before full dilation and entry into study. All women were receiving epidural anesthesia before reaching complete dilation. Labor was spontaneous or induced electively or was medically indicated. Fetal heart rate (FHR) at the time they entered the study was reassuring, and gestation was ≥38 weeks. Pain scores were ≥3 on a scale of 10 when they entered the study. This study delayed pushing up to 90 minutes at which time pushing with contractions would be encouraged. The study found that length of pushing time in the immediate pushing group (78.7 ± 7.9 min) versus the delayed pushing group (38.9 ± 6.9 min) to be 51% less in the delayed pushing group. The woman pushed sooner if she had a strong urge. The shorter duration of actual pushing time was statistically significant in the delayed pushing group versus the immediate pushing group. Duration of second stage was about 30 min shorter in the immediate pushing group (87.1 ± 8.6 min) versus delayed pushing (117.6 ± 12.1 min) but not statistically significant. Maternal fatigue, measured with the visual analog scale (VAS) was similar in the two groups. Gillesby, Burns, Dempsey, et al. (2010) had similar results with their group of 77 women, 39 in the immediate pushing group and 38 in the delayed pushing group. Their group was also nulliparas with epidural pain relief as they entered second stage. For the delayed pushing group, this RCT used 120 minutes as the maximum delay for pushing at which time pushing would be encouraged if the woman had no earlier urge. The duration of pushing time in the mothers with immediate pushing (94 ± 57 min) versus mothers with delayed pushing (68 ± 46 min) is also a statistically significant difference. Second stage labor duration averaged 107 ± 56 minutes in the immediate pushing group versus 163 ± 64 minutes in the delayed pushing group. Maternal fatigue scores were also similar with the two groups. Total second stage time was 59 minutes longer for the group who delayed pushing. Fatigue scores with the VAS were similar for the two groups. These two studies support the benefit of delaying pushing without evidence of fetal compromise. Passive fetal descent and rotation is the likely reason why the second stage, while longer in total length, requires a shorter period of pushing.

Uterine Contractions

During the first stage of labor (onset through full cervical dilation), uterine contractions are the primary force moving the fetus through the maternal pelvis.

Nursing Care During Labor and Birth Admission to the Birth Center

During the last trimester, the woman needs to know when she should go to the hospital or birth center. Nurses teach women differences between false labor and true labor and offer guidelines for going to the birth center. Not everyone has a typical labor, so a woman should be encouraged to go to the birth center if she is uncertain or has other concerns.

Contraction Cycle

Each contraction consists of three phases (Figure 16-1). The increment occurs as the contraction begins in the fundus and spreads throughout the uterus. The peak, or acme, is the period during which the contraction is most intense. The decrement is the period of decreasing intensity as the uterus relaxes. The contraction cycle and the overall pattern of contractions are also described in terms of frequency, duration, and intensity. Frequency is the period from the beginning of one uterine contraction to the beginning of the next; it is usually expressed in minutes and fractions of minutes. For example, the nurse states, "Contractions are 3½ to 4 minutes apart." Duration is the length of each contraction from beginning to end; it is usually expressed in seconds. For example, the nurse might report, "Her contractions last 55 to 65 seconds." Intensity is the strength of the contractions. The terms "mild," "moderate," and "strong" are used to describe contraction intensity as palpated by the nurse. Mild contractions are often described as feeling like the tip of the nose, moderate contractions like the chin, and firm contractions like the forehead. Different descriptions of intensity may apply when the electronic fetal monitor is used to record contractions (see Chapter 17). The interval is the period between the end of one contraction and the beginning of the next. The interval is the time when most fetal exchange of oxygen, nutrients, and waste products occurs.

Stages and Phases of Labor

Each stage and phase of labor has qualities that set it apart from the others. Individual women vary in their labor patterns and responses to labor. Table 16-1 provides details of the characteristics of each stage of labor. Use of regional anesthetics, such as the epidural block, is likely to modify the typical maternal behaviors. Also, labor that is induced or augmented often differs from spontaneous labor.

Cervical Changes

Effacement (thinning and shortening) and dilation (opening) are the major cervical changes during labor. Effacement and dilation occur together during labor but at different rates. The nullipara completes most cervical effacement early in the process of cervical dilation. In contrast, the parous woman's cervix is usually thicker than a nullipara's cervix at any point during labor.

Fetal Assessment

Estimated gestational age should be determined by prenatal care records, previous ultrasound exams, or the mother's statement about her last menstrual period. Leopold's maneuvers (see Procedure on p. 342-343) help identify the best place to assess the FHR. The rate, rhythm, and other characteristics should be assessed on admission and at intervals appropriate to the woman's risk status and labor. Fetal movement should be noted. If the membranes are ruptured, assess the color, odor, and clarity of leaking fluid. Chapter 17 provides detailed information about intrapartum fetal surveillance.

Placental Circulation

Exchange of oxygen, nutrients, and waste products between mother and fetus occurs in the intervillous spaces (see Chapter 12). During strong labor contractions, the maternal blood supply to the placenta stops intermittently as the spiral arteries supplying the intervillous spaces are compressed by the uterine muscle. Therefore most placental exchange occurs during the interval between contractions. The placental circulation usually has enough reserve over fetal basal needs to tolerate the intermittent interruption of blood flow. The fetus has protective mechanisms, such as fetal hemoglobin (which more readily takes on oxygen and releases carbon dioxide), a high hematocrit, and a high cardiac output. The fetus may not tolerate labor contractions well in conditions associated with reduced placental function, such as maternal diabetes or hypertension, or in conditions associated with reduced fetal oxygen-carrying capacity, such as fetal anemia.

EXPULSION

Expulsion occurs first as the anterior, then the posterior, shoulder passes under the symphysis. After the shoulders are born, the rest of body follows.

True Labor and False Labor

False labor, also called prodromal labor, is common because the time of spontaneous labor's onset is rarely known and the onset is usually gradual. False labor often causes women to be disappointed when their symptoms are not "the real thing." The term false labor may discourage a woman because she does not realize that these "false" contractions are simply preparation for the main event of true labor, rather than true labor itself. Several characteristics distinguish true labor from false labor: contractions, discomfort, and cervical change. The best distinction between the two is that the contractions of true labor cause progressive changes in the cervix. Effacement and dilation occur with true labor contractions.

Variations in the Passenger

Fetal Lie Attitude Presentation Cephalic Presentation Vertex

Position

Fetal position describes the location of a fixed reference point on the presenting part in relation to the four quadrants of the maternal pelvis (Figure 16-10): right and left anterior and right and left posterior. The fetal position is not fixed but rather changes during labor as the fetus moves downward and adapts to the pelvic contours. Abbreviations indicate the relationship between the fetal presenting part and the maternal pelvis.

Fetal Response

Fetal responses are most notable in the placental circulation, the cardiovascular system, and the pulmonary system.

TABLE 16-2 INTRAPARTUM ASSESSMENT GUIDE Women who have had prenatal care have much of this information available on their prenatal record. The nurse need only verify it or update it as needed. ASSESSMENT, METHOD (SELECTED RATIONALES) COMMON FINDINGS SIGNIFICANT FINDINGS, NURSING ACTION

Food intake: "When was the last time you had something to eat or drink?" "What did you have?" (Provides information needed to most safely administer general anesthesia if required. Identifies possible fluid or energy deficit.) Record the time of the woman's last food intake and what she ate. Include both liquids and solids. If the woman says she has not had any intake for an unusual length of time, question her more closely: "Is there any food you may have forgotten, such as a snack or a drink of water or other liquid?" Recent illness: "Have you been ill recently?" "What was the problem?" "What did you do for it?" "Have you been around anyone with a contagious illness recently?" Most pregnant women are healthy. An occasional woman may have had a minor illness such as an upper respiratory tract infection. Urinary tract infections are associated with preterm labor. The woman who has had contact with someone having a communicable disease may become ill and possibly infect others in the facility. Medications: "What drugs do you take that your doctor or nurse-midwife has prescribed?" "Are there any over-the-counter or herbal drugs that you use?" "I know this may be uncomfortable to discuss, but we need to know about any illegal or abused substances that you use, to more safely care for you and your baby." (Permits evaluation of the woman's drug intake and encourages her to disclose nonprescribed use.) Prenatal vitamins and iron are commonly prescribed. Record all drugs the woman takes, including time and amount of last ingestion. Women often do not consider botanical preparations as drugs. Women who use illegal substances often conceal or diminish the extent of their use because they fear reprisals. Drugs may interact with other medications given during labor, especially analgesics and anesthetics. Substance abuse is associated with complications for the mother and infant (see Chapter 24). If the woman discloses that she uses illegal drugs, ask her what kind and the last time she ingested them (often referred to as "taking a hit"). A nonjudgmental approach in private is more likely to result in honest information. Tobacco or alcohol: "Do you smoke or use tobacco in any other form? How many cigarettes a day?" "Do you use alcohol? How many drinks do you have each day (or week)?" (Evaluates use of these legal substances.) As in substance abuse, women may underreport the extent of their use of tobacco or alcohol. Infants of heavy smokers are often smaller and may have reduced placental blood flow during labor. Infants of women who use alcohol may show fetal alcohol effects at birth or later (see Chapter 30). Birth plans (shows respect for the woman and her family as individuals and promotes achievement of their expectations; enables more culturally appropriate care):

Components of the Birth Process

Four major factors, often called the "four Ps," interact during normal childbirth. They are the p owers, the p assage, the p assenger, and the p syche.

Conveying Confidence

From the first encounter, the nurse should convey confidence in the woman's ability to give birth and her partner's ability to support her. Contractions and discomfort intensify as labor progresses. A woman having her first baby may find the power of normal labor contractions overwhelming. The nurse can reassure the woman that intense contractions are normal in active labor while helping her deal with them and watching for problems.

Gastrointestinal System

Gastric motility is reduced to varying degrees during labor. Most women are not hungry but are often thirsty and have a dry mouth. Food and large volumes of liquids are usually limited to reduce the risk of vomiting and aspiration if unexpected surgery is needed. Ice chips are commonly provided, as are small amounts of other clear liquids or juices, Popsicles, or hard candy. Large amounts of sugar are not desirable because they may cause rebound hypoglycemia in the newborn when the sugar supply abruptly ends at birth.

Brow

In a brow presentation the fetal head is partly extended. The longest supraoccipitomental diameter is presenting.

Face

In a face presentation, the head is fully extended and the fetal occiput is near the fetal spine. The submentobregmatic diameter is presenting.

Database Assessment

In addition to the focused assessment, assess the mother and fetus and available maternal support.

Focused Assessment

In the intrapartum unit, an initial focused assessment is done before the broader database assessment—opposite of the usual order. Assessment priorities are to determine the condition of the mother and fetus and whether birth is imminent.

Frank breech

In the most common frank breech presentation the fetal legs are extended across the abdomen toward the shoulders.

TABLE 16-2 INTRAPARTUM ASSESSMENT GUIDE Women who have had prenatal care have much of this information available on their prenatal record. The nurse need only verify it or update it as needed. ASSESSMENT, METHOD (SELECTED RATIONALES) COMMON FINDINGS SIGNIFICANT FINDINGS, NURSING ACTION

Interview Purpose: To obtain information about the woman's pregnancy, labor, and conditions that may affect her care. The interview is curtailed if she is in late labor. Introduction: Introduce yourself, and ask the woman how she wants to be addressed. Ask her if she wants her partner and/or family to remain during the interview and assessment. (Shows respect for the woman and gives her control over those she wants to remain with her.) Many women prefer to be addressed by their first names during labor. The surname (family name) precedes the given name in some cultures. Clarify which name is used to properly address the woman and to properly identify both mother and newborn. Have the woman verify accuracy of identification bands before placing them on her and baby. Culture and language: If she is from another culture, ask what her preferred language is and what language(s) she speaks, reads, or verbally understands. (Identifies the need for an interpreter and enables the most accurate data collection.) Common non-English languages of women in the United States are Spanish and some Asian dialects. The most common non-English language varies with location. Secure an interpreter fluent in the woman's primary language. Ask her if there are people who are not acceptable to her as interpreters (e.g., males or members of a group in conflict with her culture). Family members may not be the best interpreters because they may interpret selectively, adding or subtracting information as they see fit. Phone interpreters are available in many facilities. Hearing-impaired women may read lips well, or they may need sign-language interpreters or other assistance. Communication: Ask the woman to tell you when she has a contraction, and pause during the interview and physical assessment. (Shows sensitivity to her comfort and allows her to concentrate more fully on the information the nurse requests.) Women in active labor have difficulty answering questions or cooperating with a physical examination while they are having a contraction. Consider the stage and phase of labor to determine what information can wait. If contractions are very frequent, assess the woman's labor status promptly rather than continuing the interview. Ask only the most critical questions (see p. 336). Nonverbal cues: Observe the woman's behaviors and interactions with her family and the nurse. (Permits estimation of her level of anxiety. Identifies behaviors indicating that she should have a vaginal examination to determine whether birth is imminent.) Latent phase: Woman is sociable and mildly anxious. Active phase: Woman concentrates intently during contractions; often uses prepared childbirth techniques. The unprepared or extremely anxious woman may breathe deeply and rapidly, displaying a tense facial and body posture during and between contractions. These behaviors suggest that birth is imminent: 1.Her statement that the baby is coming. 2.Grunting sounds (low-pitched, guttural sounds). 3.Bearing down with abdominal muscles. 4.Sitting on one buttock Euphoria, combativeness, or sedation suggests recent illicit drug ingestion. Reason for admission: "What brings you to the hospital/birth center today?" (Open-ended question promotes more complete answer.) Labor contractions at term, induction of labor, or observation for false labor are common reasons for admission. Bleeding, preterm labor, pain other than labor contractions. Report these findings to the physician or nurse-midwife promptly.

Physiologic Effects of the Birth Process

Labor and birth affect the physiologic systems of both the pregnant woman and her fetus. These effects are most striking in the maternal reproductive system and in relation to fetal and neonatal oxygenation.

Normal Labor Theories of Onset

Labor begins when forces favoring continuation of pregnancy are overcome by forces favoring its end. The body's preparation to give birth occurs gradually over the last few weeks of pregnancy. Although all reasons for initiation of labor are not known, factors that have a role in its onset include (Cunningham et al., 2010; Hall, 2011; Norwitz & Lye, 2009): •Changes in the ratio of maternal estrogen to progesterone so that estrogen levels are higher than progesterone levels, reducing the relaxant effects of progesterone on the uterine muscle. Relatively higher estrogen levels near the onset of labor enhance uterine sensitivity to substances that stimulate uterine contractions: prostaglandins from the fetal membranes and oxytocin from the maternal posterior pituitary gland. Estrogens increase the number of gap junctions—connections that allow the individual uterine muscle cells to contract as a coordinated unit. •Prostaglandins produced by the decidua and membranes may have a role in preparing the uterus for oxytocin stimulation at term. Prostaglandins are secreted from the lower area of the fetal membranes (forebag) during labor and may reflect inflammation caused by contact with microorganisms from the woman's vagina. •Increased secretion of natural oxytocin appears to maintain labor once it has begun. Oxytocin alone does not appear to start labor but may play a part in labor's initiation in conjunction with other substances. Evidence of fetal oxytocin secretion also exists. •Oxytocin receptors in the uterus increase markedly as labor begins, and the increase continues during labor and peaks at delivery. Oxytocin has little effect on the uterine muscle if the receptors have not developed. •A fetal role in the initiation of labor appears likely. The fetal membranes release prostaglandin in high concentrations during labor. In addition to fetal oxytocin secretion, large quantities of cortisol are secreted by the fetal adrenal, possibly acting as a uterine stimulant. •Stretching, pressure, and irritation of the uterus and cervix increase as the fetus reaches term size. During early pregnancy, the uterus has not reacted to stretching by contracting as smooth muscle normally does. A feedback loop is probably responsible for labor contractions at term: the fetal head stretches the cervix, causing the fundus of the uterus to contract, pushing the fetal head against the cervix, and causing more fundal contractions. Cervical stretching also causes secretion of oxytocin.

Intermittent Contractions

Labor contractions are intermittent rather than sustained, allowing relaxation of the uterine muscle and resumption of blood flow to and from the placenta to permit gas, nutrient, and waste exchange for the fetus.

Unpredictability

Labor is a natural process that follows its own timetable. Some occurrences simply are not easily predicted or explained. Some nurses find the uncertain nature of intrapartum care troubling, whereas others find it exciting. Some days are busy from the start, whereas others are uncannily quiet, only to erupt in adrenaline-charged action with no warning.

Hematopoietic System

Many authorities recognize 500 mL as a normal average blood loss during vaginal birth although women may often lose and tolerate greater loss well because the blood volume increases during pregnancy by 1 to 2 L. Quantitative rather than estimated blood loss is often higher than the estimate. A hemoglobin of 11 g/dL and a hematocrit of 33% or higher give most women an adequate margin of safety for blood loss associated with normal birth. The leukocyte count averages 14,000 to 16,000/mm3 but may be as high as 25,000/ mm3 or higher during labor, a level that might otherwise suggest infection (Blackburn, 2013; Cunningham, Leveno, Bloom, et al., 2010; Hall, 2011). Levels of several clotting factors, especially fibrinogen, are elevated during pregnancy and continue to be higher during labor and after delivery. Fibrinolysis (clot breakdown) decreases during labor to promote coagulation at the placental site. Although the increase in clotting factors and decrease in fibrinolysis protect from hemorrhage, the combination also raises the mother's risk for venous thrombosis during pregnancy and after birth.

Basic Information

Most intrapartum admission forms guide the nurse to ask for essential information. Prenatal records may be available to answer many of these questions if the woman had regular visits. Typical information includes: •The woman's reason for coming to the hospital or birth center (e.g., contractions, rupture of membranes, bleeding) •Prenatal care: when it began, most recent visit, name of physician or nurse-midwife •EDD •Number of pregnancies, births, spontaneous pregnancy losses (miscarriage), and abortions •Allergies (medications, food, substances such as latex) •Food intake: what food and when it was eaten •Medical, surgical, and pregnancy history •Recent illness, including treatment •Medications, including prescription and over-the-counter drugs •Complementary or alternative therapy; use of herbal and botanical preparations and their purpose •Use of tobacco, alcohol, and substances of abuse •Her subjective evaluation of her labor •Birth plans, including expected pain management methods •Support persons: who they are and the role of each •Screening for domestic violence when woman is alone (see Chapter 24) Be careful when discussing prior pregnancies and births when a woman's family is present. She may have had an abortion or relinquished a baby for adoption, and her family may not know about it. Even if her partner knows about previous pregnancies, other family and friends may not.

Characteristics of Contractions

Normal labor contractions are coordinated, involuntary, and intermittent.

Impending Birth

Occasionally a woman enters the intrapartum unit almost ready to give birth. Grunting sounds, bearing down, sitting on one buttock, or saying urgently something like "The baby's coming" suggests imminent birth. The nurse abbreviates the initial assessment and collects other information when possible. Vital information to obtain if birth is imminent includes: •Mother's name •Support person's name •Whether the woman had prenatal care •Physician's or nurse-midwife's name •Number of pregnancies and prior births, including whether vaginal or cesarean birth •Status of membranes •Estimated date of delivery (EDD) •Any problems during this pregnancy •Medications (see Database Assessment) •Allergies •Time and type of last oral intake •Maternal vital signs and FHR •Pain: location, intensity, intensifying or relieving factors, duration, whether it is constant or intermittent, acceptability to the woman If focused assessments of mother and fetus are normal and birth is not imminent, complete the admission assessment. If the initial assessments are not normal or birth is near, notify the physician or nurse-midwife promptly.

TABLE 16-2 INTRAPARTUM ASSESSMENT GUIDE Women who have had prenatal care have much of this information available on their prenatal record. The nurse need only verify it or update it as needed. ASSESSMENT, METHOD (SELECTED RATIONALES) COMMON FINDINGS SIGNIFICANT FINDINGS, NURSING ACTION

Prenatal care: "Did you see a doctor or nurse-midwife during your pregnancy?" "Who is your doctor or nurse-midwife?" "How far along were you in your pregnancy when you saw the physician or nurse-midwife?" "Have you ever been admitted here before during this pregnancy?" (Enables location of prenatal record and prior visit records.) Early and regular prenatal care promotes maternal and fetal health. No prenatal care or care that was irregular or begun in late pregnancy means that complications may not have been identified. Estimated date of delivery (EDD): "When is your baby due?" (Determines if gestation is term.) "When did your last menstrual period begin?" (For estimation of EDD if woman did not have prenatal care.) Term gestation: 38-42 weeks. The woman's gestation may have been confirmed or adjusted during pregnancy with an ultrasound or other clinical examination. Gestations earlier than the beginning of the 38th week (preterm) or later than the end of the 42nd week (postterm) are associated with more fetal or neonatal problems. The physician may try to stop labor that occurs earlier than 36 weeks if there are no contraindications for mother or fetus. Gravidity, parity, abortions: "How many times have you been pregnant?" "How many babies have you had? Were they full term or premature?" "How many children are now living?" "Have you had any miscarriages or abortions?" "Were there any problems with your babies after they were born?" (Helps estimate probable speed of labor and anticipate neonatal problems.) Labor may be faster for the woman who has given birth before than for the nullipara. Miscarriage is used to describe a spontaneous abortion because many lay people associate the term abortion with only induced abortions. Parity of 5 or more (grand multiparity) is associated with placenta previa (see Chapter 25) and postpartum hemorrhage (see Chapter 28). Women who have had several spontaneous abortions or who have given birth to infants with abnormalities may face a higher risk for an infant with a birth defect. Pregnancy history (Identifies problems that may affect this birth.) Present pregnancy: "Have you had any problems during this pregnancy, such as high blood pressure, diabetes, infections, or bleeding?" Complications are not expected. Women who have diabetes or hypertension may have poor placental blood flow, possibly resulting in fetal compromise. Some complications of past pregnancies, such as gestational diabetes, may recur in another pregnancy. The woman who plans a VBAC may need more support and reassurance to give birth vaginally. Past pregnancies: "Were there any problems with your other pregnancy(ies)?" "Were your other babies born vaginally or by cesarean birth?" Women who had previous cesarean birth(s) may have a trial of labor and vaginal birth (VBAC). A woman who previously had a difficult labor or a cesarean birth may be more anxious than one who had an uncomplicated labor and birth. Although the VBAC is less common, it may be chosen for a variety of reasons. The nurse should be aware of the need for support and for complications that may be more likely in the current pregnancy. Other: "Is there anything else you think we should know so that we can better care for you?" This open-ended question gives the woman a chance to share information that may not be elicited by other questions. Labor status: "When did your contractions become regular?" "What time did you begin to think you might really be in labor?" (Facilitates a more accurate estimation of the time labor began.) Varies among women. Many women go to the birth facility when contractions first begin. Others wait until they are reasonably sure that they are really in labor. Women who say they have been "in labor" for an unusual length of time (e.g., "for 2 days") have probably had false (prodromal) labor. These women may be very tired from the annoying and apparently nonproductive contractions. Contractions: "How often are your contractions coming?" "How long do they last?" "Are they getting stronger?" "Tell me if you have a contraction while we are talking." (Obtains the woman's subjective evaluation of her contractions. Alerts the nurse to palpate contractions that occur during the interview.) Varies according to her stage and phase of labor. Labor contractions are usually regular and show a pattern of increasing frequency, duration, and intensity. Irregular contractions or those that do not increase in frequency, duration, or intensity are more likely to represent false labor. Contractions that are too frequent or too long can reduce placental blood flow. Incomplete uterine relaxation between contractions also can reduce placental blood flow (see Chapter 17). Membrane status: "Has your water broken?" "What time did it break?" "What did the fluid look like?" "About how much fluid did you lose—was it a big gush or a trickle?" (Alerts the nurse of the need to verify whether the membranes have ruptured if it is not obvious. Identifies possible prolonged rupture of membranes or preterm rupture.) Most women go to the birth facility for evaluation soon after their membranes rupture. If a woman is not already in labor, contractions usually begin within a few hours after the membranes rupture at term. If the woman's membranes have ruptured and she is not in labor or if she is not at term, a vaginal examination is often deferred. A speculum examination may be done by the physician or nurse-midwife to identify the woman's membrane status. Labor may be induced if she is at term with ruptured membranes. Allergies: "Are you allergic to any foods, medicines, or other substances?" "Do you have an allergy to latex?" "What kind of reaction do you have?" "Have you ever had a problem with anesthesia when you have had dental work?" (Determines possible sensitivity to drugs that may be used.) Record any known allergies to food, medication, or other substances. As needed, describe how they affected the woman. Allergy to seafood, iodized salt, or imaging contrast media may indicate iodine allergy. Because iodine is used in many "prep" solutions, alternative ones should be used. Allergy to latex is more common. Allergy to dental anesthetics may indicate possible allergy to the drugs used for local or regional anesthetics. These drugs usually end in the suffix -caine.

Determining Family Expectations about Birth

Regardless of how many children they have, women and their partners have expectations about the birth experience. The partners have often studied their options extensively and have planned a birth that best fits their ideals. Some may have a written birth plan filed with their prenatal records. Those who have not made specific plans also have expectations shaped by contact with relatives and friends or by previous birth experiences. Most women assume that their partner, usually the baby's father, will be present. Many want other close and trusted family or friends to be with them for all or part of labor and birth (Price, Noseworthy, & Thornton, 2007). Consider the different perspective implied by the phrases "give birth" and "be delivered." The woman who gives birth is an active and able participant; she is the principal action figure. When her baby is "delivered," however, the language implies that she is passive. The nurse might ask, "Who will attend you as you give birth?" or "Who is your doctor [or midwife]?" rather than, "Who will deliver your baby?"

Maternal Response

Significant changes during labor occur in the woman's cardiovascular, respiratory, gastrointestinal, urinary, and hematopoietic systems as well as in her reproductive system.

Attitude

The attitude of the fetus is the relation of fetal body parts to each other (Figure 16-7, p. 324). The normal fetal attitude is one of flexion, with the head flexed toward the chest and the arms and legs flexed over the thorax. The back is curved in a convex C shape as labor starts.

Cephalic Presentation

The cephalic presentation is more favorable than others, for several reasons: •The fetal head is the largest single fetal part. After the head is born, the smaller parts follow easily as the extremities unfold. •During labor the fetal head can gradually change shape to adapt to the size and shape of the maternal pelvis. •The fetal head is smooth, round, and hard, making it an effective part to dilate the cervix, which is also round. Cephalic presentation has four variations. Four types of cephalic presentation. The vertex presentation is normal. Note positional changes of the anterior and posterior fontanels in relation to the maternal pelvis. (refer to figure 16-8 important)

Active Phase

The cervix dilates more rapidly as the woman enters the active phase, between about 4 cm and 6 cm. Research has demonstrated safety in a slower transition between latent and active labor than usually accepted in women in spontaneous labor (Zhang, Landry, Branch, et al., 2010). Effacement and dilation of the cervix are completed. Internal rotation occurs as the fetus descends in the pelvis during active labor. Discomfort usually increases as the pace of labor picks up. Transition may be used to describe the intense contractions of fetal descent and final cervical dilation, about 7 or 8 cm to complete. Maternal discomfort and behaviors often vary with pain-relief method chosen. Bloody show often increases with completion of cervical dilation. Transition is a short but intense phase, with very strong contractions. The woman may have an urge to push down during contractions as the fetal presenting part reaches her pelvic floor. Leg tremors, nausea, and vomiting are common as second stage nears. The woman becomes more anxious and may feel irritable and helpless as the contractions intensify. The sociability of early labor is gone, replaced with a serious, inward focus. Her partner may be confused because actions that were helpful just a short time before now bother her.

Respiratory System

The depth and rate of respirations increase, especially if the woman is anxious or in pain. A woman who breathes rapidly and deeply may experience symptoms of hyperventilation if she exhales too much carbon dioxide. She may feel tingling in her hands and feet, numbness, and dizziness. Helping her to slow her breathing and to breathe into a paper bag or her cupped hands can restore normal blood levels of carbon dioxide and relieve these symptoms.

Fetal Cardiovascular System

The fetal cardiovascular system reacts quickly to events during labor. The fetal heart rate (FHR) is rapid, ranging from 110 to 160 beats per minute (bpm) at term (Lyndon, O'Brien-Abel, & Simpson, 2009). The preterm fetus may have a slightly higher heart rate than the term fetus, although persistent high FHRs at any gestation should be investigated (see Chapter 17 for more discussion of FHR and responses during labor).

Presentation

The fetal part that enters the pelvis first is the presenting part. Presentation falls into three categories: (1) cephalic, (2) breech, and (3) shoulder. The cephalic presentation with the fetal head flexed is the most common (Figure 16-8, p. 325). Other presentations are associated with prolonged labor or other problems and are more likely to require cesarean birth.

Fetal Head

The fetus enters the birth canal in the cephalic presentation more than 96% of the time. The fetal shoulders are important because of their width, but they usually flex and adapt to the pelvis.

Internal Rotation

The fetus enters the pelvic inlet with the sagittal suture in a transverse or oblique orientation to the maternal pelvis because that is the widest inlet diameter. Internal rotation allows the longest fetal head diameter (the anteroposterior) to conform to the longest diameter of the maternal pelvis. The longest pelvic outlet diameter is the anteroposterior. As the head descends to the level of the ischial spines, it gradually turns so that the fetal occiput is in the anterior of the pelvis (OA position, directly under the maternal symphysis pubis). When internal rotation is complete, the sagittal suture is oriented in the anteroposterior pelvic diameter (OA). Less commonly, the head may turn posteriorly so that the occiput is directed toward the mother's sacrum (OP).

Right (R) or Left (L)

The first letter of the abbreviation describes whether the fetal reference point is in the right or the left of the mother's pelvis. If the fetal point is neither to the right nor to the left of the pelvis, this letter is omitted.

Footling breech

The footling breech occurs when one or both feet are presenting.

Interrelationships of the Components of Birth

The four Ps—the powers, passage, passenger, and psyche—are an interrelated whole. For example, a woman with a small pelvis (passage) and a large fetus (passenger) can have a normal labor and birth if the fetus is ideally positioned and the uterine contractions and maternal bearing-down efforts (powers) are vigorous. The nurse's supportive attitude strengthens positive psychological elements (psyche) and enhances the processes of birth. The nurse can act as an advocate for the laboring woman and her family or partners to increase their sense of control and mastery of labor, often reducing anxiety and fear.

Fourth Stage of Labor

The fourth stage of labor is the stage of physical recovery for the mother and infant. It lasts from the delivery of the placenta through the first 1 to 4 hours after birth. Immediately after birth, the firmly contracted uterus can be palpated through the abdominal wall as a firm, rounded mass about 10 to 15 cm (4 to 6 in) in diameter at or below the level of the umbilicus. The uterus is larger when the infant is large or the mother is a multipara. Uterine size is larger in the women who delivered twins or more at or near term. The vaginal drainage during the fourth stage is lochia rubra, which consists mostly of blood. Small clots may also be present. See Chapter 20 for more information about lochia. Many women have a chill after birth. The chill lasts for about 20 minutes and subsides spontaneously. A warm blanket, hot drink, or soup may help shorten the chill and make the woman more comfortable. Discomfort during the fourth stage usually results from birth trauma or afterpains. Ice packs on the perineum limit discomfort and hematoma formation. Afterpains are uterine contractions similar to menstrual cramps that occur after birth as the uterus begins its return to the prepregnancy state. The discomfort is similar to that of menstrual cramps. Afterpains are more intense in multiparas, in women who breastfeed, in women who have large babies or other causes of uterine overdistention during pregnancy, or when something interferes with uterine contraction, such as a full bladder or a blood clot that remains in the uterus. The mother is simultaneously excited and tired after birth. She may be exhausted but too full of nervous energy to rest. The fourth stage of labor is an ideal time for bonding of the new family because the interest of both parents and newborn is high. It is also the best time to start breastfeeding if no maternal or infant problems are present. The baby is alert and seeks to make eye contact with the new parents, giving powerful reinforcement for the parents' attachment to their newborn.

Full (or complete) breech

The full breech is a reversal of the usual cephalic presentation. The head is flexed, and the knees and hips are also flexed, but the buttocks are presenting.

Intimacy

The intimate nature of intrapartum care and its sexual overtones also make some nurses uncomfortable. They may feel that they are intruding on a private time. The male nurse often finds this aspect of intrapartum care most anxiety provoking. Although he may have cared for other female clients, his care has not been this focused on the reproductive system. He often wonders how a woman's male partner will accept him as a care provider. The best approach for both male and female nurses is to maintain professional conduct and take cues from the couple. If they want privacy, the nurse should intervene only as needed to assess the woman and fetus. In more advanced labor, both partners often welcome the presence of a competent, caring nurse of either sex.

Latent Phase

The latent, or early, phase lasts from the beginning of labor until about 3 to 5 cm of cervical dilation. Its length varies among women. Despite being called latent, cervical effacement and subtle fetal position change occur during this phase, preparing for more rapid changes of active labor. The woman is usually sociable and excited during this early phase of labor.

Mechanisms of Labor

The mechanisms (cardinal movements) of labor occur as the fetus is moved through the pelvis during birth. The fetus undergoes several positional changes to adapt to the size and shape of the mother's pelvis at different levels (Figure 16-12). Although the mechanisms of labor are described separately in Figure 16-12, (pp. 330-331) some occur concurrently. In a vertex presentation, the mechanisms are: •Descent of the fetal presenting part through the true pelvis. •Engagement of the fetal presenting part as its widest diameter reaches the level of the ischial spines of the mother's pelvis. •Flexion of the fetal head so that the smallest head diameters pass through the pelvis. •Internal rotation to allow the largest fetal head diameters to match the largest maternal pelvic diameters. •Extension of the fetal head as it passes beneath the mother's symphysis pubis. •External rotation of the fetal head to allow the shoulders to rotate internally to fit the mother's pelvis. •Expulsion of the fetal shoulders and fetal body.

Urinary System

The most common change in the urinary system during labor is reduced sensation of a full bladder. Because of intense contractions or the effects of regional pain management such as epidural, the woman may be unaware that her bladder is full. Yet a full bladder may contribute to general discomfort that remains after regional analgesia. A full bladder can also inhibit fetal descent because it occupies space in the pelvis. After birth, the fluid retention that is normal during pregnancy is quickly reversed, and urine is excreted in large quantities. The bladder may fill rapidly during the first few days after birth.

Nursing Care During Labor and Birth Nursing Responsibilities during Admission

The nurse has two priorities when the woman arrives at the birth center: (1) establishing a therapeutic relationship while (2) assessing the condition of the mother and fetus.

Inexperience or Negative Experiences

The nurse who has never given birth may feel inadequate to care for laboring women, although she or he rarely feels it necessary to have a fracture to care for someone with that problem. Nursing skills needed by the intrapartum nurse are basic: observation, critical thinking, problem solving, therapeutic communication, comfort promotion, empathy, and common sense. Nurses also may be anxious because of their own difficult experiences during pregnancy or birth. They must be careful not to convey negative attitudes to the laboring woman and her partner.

Fetal Lie

The orientation of the long axis of the fetus to the long axis of the woman is the fetal lie (Figure 16-6, p. 324). In more than 99% of pregnancies, the lie is longitudinal, or parallel to the long axis of the woman. In the longitudinal lie, either the head or buttocks of the fetus enter the pelvis first. A transverse lie exists when the long axis of the fetus is at right angles to the woman's long axis; it occurs in less than 1% of pregnancies. An oblique lie is one at some angle between the longitudinal lie and the transverse lie.

Passage

The passage for birth of the fetus consists of the maternal pelvis and its soft tissues. The bony pelvis is usually more important to the outcome of labor than the soft tissue because the bones and joints do not readily yield to the forces of labor. However, softening of the cartilage linking the pelvic bones increases as term approaches and the hormone relaxin increases. The bony pelvis is divided by the linea terminalis (or pelvic brim) into the false pelvis above and the true pelvis below (see Chapter 11). The true pelvis is most important in childbirth. The true pelvis has three subdivisions: (1) the inlet, or upper pelvic opening; (2) the midpelvis, or pelvic cavity; and (3) the outlet, or lower pelvic opening. The true pelvis is like a curved cylinder with different dimensions at different levels. Figure 16-4 (pp. 322-323) illustrates important pelvic measurements.

Passenger

The passenger is the fetus plus the membranes and placenta.

Psyche

The psyche is a crucial part of childbirth. Marked anxiety, fear, or fatigue decreases a woman's ability to cope with pain in labor. Maternal catecholamines secreted in response to anxiety or fear can inhibit uterine contractility and placental blood flow. Relaxation, however, augments the natural process of labor.

Occiput (O), Mentum (M), or Sacrum (S)

The second letter of the abbreviation refers to the fixed fetal reference point, which varies with the presentation. The occiput is used in a vertex presentation. The chin, or mentum, is the reference point in a face presentation. The sacrum is used for breech presentations. Letters may also designate the less common brow (F for fronto) and shoulder (Sc for scapula) presentations.

Second Stage of Labor

The second stage (expulsion) begins with complete (10 cm) dilation and full (100%) effacement of the cervix and ends with the birth of the baby. As the fetus descends, pressure of the presenting part on the rectum and the pelvic floor causes the mother to have an involuntary pushing response. She may say that she needs to have a bowel movement or "The baby's coming" or "I have to push." Her voluntary pushing efforts augment involuntary uterine contractions. As the fetus descends low in the pelvis and the vulva distends with crowning of the fetal head, she may feel a sensation of stretching or splitting even if no trauma occurs. Contractions are strong, but the woman may feel more in control because she is actively completing the process by pushing with them. "Labor" describes the second stage well. The woman exerts intense effort to push her baby out. Between contractions she may be oblivious to her surroundings and may appear asleep. She feels tremendous relief and excitement as the second stage ends with the birth of her baby.

Shoulder

The shoulder presentation is a transverse lie and accounts for fewer than 1% of births, usually premature (Cunningham et al., 2010; Tarsa & Moore, 2010). A cesarean birth is necessary.

Third Stage of Labor

The third (placental) stage begins with the birth of the baby and ends with the expulsion of the placenta (Figure 16-14). When the infant is born, the uterine cavity becomes much smaller. The reduced size decreases the size of the placental site, causing the placenta to separate from the uterine wall. Four signs suggest placenta separation: •The uterus has a spherical shape. •The uterus rises upward in the abdomen as the placenta descends into the vagina and pushes the fundus upward. •The cord descends further from the vagina. •A gush of blood appears as blood trapped behind the placenta is released. The placenta may be expelled in one of two ways. In the more common Schultze mechanism, the placenta is expelled with the shiny, fetal side first (see Figure 16-14, A). The Duncan mechanism is less common, with the rough maternal side presenting (see Figure 16-14, B). The uterus must contract firmly and remain contracted after the placenta is expelled to compress open vessels at the implantation site. Inadequate uterine contraction after birth may result in hemorrhage. Pain during the third stage of labor results from uterine contractions and brief stretching of the cervix as the placenta passes through it.

Anterior (A), Posterior (P), or Transverse (T)

The third letter describes whether the fetal reference point is in the anterior or the posterior quadrant of the mother's pelvis. If the fetal reference point is in neither the anterior nor the posterior quadrant, it is described as transverse. If the fetal occiput is located in the left anterior quadrant of the mother's pelvis, the position is described as left occiput anterior (LOA). If the occiput is in the mother's anterior pelvis, neither to the right nor to the left, it is described as occiput anterior (OA). If the fetal sacrum is located in the mother's right posterior pelvis, the description is R (right) S (sacrum) P (posterior). See Figure 16-11 for different fetal presentations and positions.

Duration of Labor

The total duration of labor is different for women who have never given birth and for those who have previously given birth vaginally. The parous woman usually delivers more quickly than does the nulliparous woman. Women, however, are individuals. Some nulliparas progress through labor quickly, whereas labor for some parous women resembles that of women who have never given birth. A woman who experienced a long labor with her first child may not have a long labor with every baby. If she has a history of rapid labor, however, later births are often rapid as well.

Powers

The two powers of labor are uterine contractions and maternal pushing efforts.

Coordinated Contractions

The uterus can contract and relax in a coordinated way, as can other smooth muscles such as the heart. As the woman approaches full term, contractions become organized and gradually assume a regular pattern of increasing frequency, duration, and intensity during labor. Coordinated labor contractions begin in the uterine fundus and spread downward toward the cervix to propel the fetus through the pelvis.

Vertex

The vertex presentation is the most common cephalic presentation. The fetal head is fully flexed. This presentation is the most favorable for normal progress of labor because the smallest suboccipitobregmatic diameter is presenting.

PATIENT-CENTERED TEACHING: When to Go to the Hospital or Birth Center

These are guidelines for providing individualized instruction to women about when to enter the hospital or birth center. Contractions • A pattern of increasing regularity, frequency, duration, and intensity. • Nullipara: Regular contractions, 5 minutes apart, for 1 hour. • Multipara: Regular contractions, 10 minutes apart, for 1 hour. Ruptured Membranes A gush or trickle of fluid from the vagina should be evaluated, whether or not you have contractions, to determine if your membranes have ruptured (if your "water has broken"). Bleeding Bright red bleeding that is not mixed with mucus should be evaluated promptly. Normal bloody show is thicker, pink or dark red, and mixed with mucus. Decreased Fetal Movement If you notice a decrease in the baby's movement, notify your physician or nurse-midwife or go to the labor unit. Other Concerns These guidelines cannot cover all situations. Therefore go to the birth center for evaluation of any concerns or feelings that something may be wrong.

Using Touch for Comfort

Touch can communicate acceptance and reassurance and can provide physical and emotional comfort to many laboring women. Women who do not usually welcome touch may appreciate it during labor. Cultural norms and personal history influence whether a woman is comfortable with touch from a stranger such as a nurse. One should not assume that the woman desires touch but should ask her if she wants it or benefits from it. As labor progresses, touch may become an irritant rather than a comfort measure during late labor.

Uterine Body

Uterine activity during labor is characterized by opposing features. The upper two thirds of the uterus contracts actively to push the fetus down. The lower one third of the uterus remains less active, allowing downward passage of the fetus. The cervix is similar to the lower uterine segment in that it is also passive. The net effect of labor contractions is enhanced because the downward push from the upper uterus is accompanied by reduced resistance to fetal descent in the lower uterus. Myometrial (uterine muscle) cells in the upper uterus remain shorter at the end of each contraction rather than returning to their original length. In contrast, myometrial cells in the lower uterus become longer with each contraction. These two characteristics enable the upper uterus to maintain tension between contractions to preserve the cervical changes and downward fetal progress made with each contraction. The opposing characteristics of myometrial contraction in the upper and lower uterine segments cause changes in the thickness of the uterine wall during labor. The upper uterus becomes thicker while the lower uterus becomes thinner and pulled upward during labor. The physiologic retraction ring marks the division between the upper and lower segments of the uterus (Figure 16-2). The opposing characteristics of contractions in the upper and lower uterine segments change the shape of the uterine cavity, which becomes more elongated and narrower as labor progresses. This change in uterine shape straightens the fetal body and efficiently directs it downward in the pelvis.

Involuntary Contractions

Uterine contractions are not under conscious control, as are skeletal muscles. The mother cannot cause labor to start or stop by conscious effort. Walking or other activity may stimulate existing labor contractions. Anxiety and excessive stress can diminish them.

EXTERNAL ROTATION

When the head is born with the occiput directed anteriorly, the shoulders must rotate internally so that they align with the anteroposterior diameter of the pelvis. After the head is born, it spontaneously turns to the same side as it was in utero as it realigns with the shoulders and back (through a process called restitution). The head then turns farther to that side in external rotation as the shoulders internally rotate and are positioned with their transverse diameter in the anteroposterior diameter of the pelvic outlet. External rotation of the head accompanies internal rotation of the shoulders.

CHARACTERISTICS OF NORMAL LABOR FIRST STAGE SECOND STAGE THIRD STAGE FOURTH STAGE

Work accomplished 1st: Effacement and dilation of cervix 2nd: Expulsion of fetus 3rd: Separation of placenta 4th: Physical recovery and bonding with newborn Forces Uterine contractions Uterine contractions and voluntary bearing-down efforts Uterine contractions Uterine contraction to control bleeding from placental site Average duration Nullipara Latent phase: approximately 7.5-8.5 hr Active phase: 8-10 hr (range, 6-18 hr); dilation averages 1.2 cm/hr Transition phase: approximately 3.5 hr Average, 50 min (range, 30 min-3 hr) 5-10 min; up to 30 min is normal for unassisted placental separation 1-4 hr after birth Multipara Latent phase: approximately 4-5.5 hr Active phase: 6-7 hr (range, 2-10 hr); dilation averages 1.5 cm/hr Transition phase: 0-30 min Average, 20 min (range 0-30 min) Same as for nullipara Same as for nullipara Cervical dilation Latent phase: 0-3 cm Active phase: 4-10 cm Transition phase (if used): final 8-10 cm 10 cm (complete dilation) Not applicable Not applicable Uterine contractions Latent phase: Initially mild and infrequent; progress to moderate strength, every 5 min with a regular pattern; duration increases to 30-40 sec by end of latent phase Active phase: Increase in frequency, duration, and intensity until every 2-3 min, 40-60 sec, and moderate to strong intensity Transition phase(if used): Strong, every 1½-2 min, 60-90 sec Strong, every 2-3 min, lasting 40-60 sec; may be slightly less intense than during transition phase of first stage; may pause briefly as second stage begins Firmly contracted Firmly contracted Discomfort∗ Often begins with a low backache and sensations similar to those of menstrual cramps; back discomfort gradually sweeps to lower abdomen in a girdlelike fashion; discomfort intensifies as labor progresses Urge to push or bear down with contractions, which becomes stronger as fetus descends; distention of vagina and vulva may cause a stretching or splitting sensation Little discomfort; sometimes slight cramp is felt as placenta is passed Discomfort varies; some women have afterpains, more common in multigravidas or those who have had a large baby; as anesthesia wears off, perineal discomfort may become noticeable Maternal behaviors∗ Sociable, excited, and somewhat anxious during early labor; becomes more inwardly focused as labor intensifies; may lose control during transition Intense concentration on pushing with contractions; often oblivious to surroundings and appears to doze between contractions Excited and relieved after baby's birth; usually very tired; often cries Tired, but may find it difficult to rest because of excitement; eager to become acquainted with her newborn

Pain Associated with Birth

Working with people in pain is difficult, and most nurses feel compelled to relieve pain promptly. Yet pain is an expected part of labor and cannot be eliminated. Helping the woman manage the pain of birth is a crucial part of nursing care.

Station Station

describes the descent of the fetal presenting part in relation to the level of the ischial spines. The level of the ischial spines is a zero station. Other stations are described with numbers representing the approximate number of centimeters above (negative numbers) or below (positive numbers) the ischial spines. As the fetus descends through the pelvis, the station changes from higher negative numbers (−3, −2, −1) to zero to higher positive numbers (+1, +2, +3, etc.). Sometimes the terms floating or ballottable may describe a fetal presenting part that is so high that it is easily displaced upward during abdominal or vaginal examination, similar to tossing a ball upward. Engagement Engagement occurs when the largest diameter of the fetal presenting part (normally the head) has passed the pelvic inlet and entered the pelvic cavity. Engagement is presumed to have occurred when the station of the presenting part is zero or lower. Engagement often takes place before onset of labor in nulliparous women. In many parous women and in some nulliparas, it does not occur until after labor begins. Flexion As the fetus descends, the fetal head is flexed farther as it meets resistance from the soft tissues of the pelvis. Head flexion presents the smallest anteroposterior diameter (suboccipitobregmatic) to the pelvis.