OB Ch 16: Labor & Delivery

bony pelvis

- can be divided into two parts, the false pelvis and the true pelvis

Joints of the pelvis

- symphysis pubis - right and left sacroiliac joints - These joints become mobile in pregnancy because of the effects of increased estrogen and relaxin levels, allowing the pelvis to conform to the fetal passage

Stage 2: Expulsion

Childbirth reaches 2nd stage when cervix is fully dilated to 10 cm - This stage ends with the birth of the infant. - Early in this stage, woman experiences a lull between the end of dilation and the beginning of the urge to push known as the latency period. - Delaying pushing until the patient feels the urge to push may reduce maternal fatigue (Ferguson reflex typically starts when the presenting part is at station +1.) - woman should push according to her preferences and the recommendations of her obstetric provider in accordance with the clinical situation - stage may last as little as 20 minutes for some women who have given birth before or may last for hours for a subset of women who are giving birth for the first time

complete breech

Fetus is sitting with legs crossed.

Chart Review

If the woman's chart is not already on the unit, a copy is ordered as soon as she presents to the unit. This prenatal record includes all visit information, including laboratory studies, ultrasounds, and pertinent information about each visit. - Patient medications, allergies, prior obstetric history, and the estimated date of delivery are carefully reviewed. - Particular note is made of conditions such as preeclampsia, diabetes, known cardiac conditions, and other health issues that may complicate labor, delivery, or the postpartum period. - For patients known to be group B streptococcus positive, antibiotics are started when labor is confirmed per orders - Maternal Rh status is also noted. The woman's birth plan is reviewed with her nurse at this time.

Precipitous labor

Labor that lasts 3 hours or less from onset of contractions to time of delivery

Nesting

Some women may experience an urge to put everything in order and clean as labor approaches. However, this surge of energy may result more from wishful thinking than any physical change, as a woman anticipates the nesting urge as proof of impending labor.

Four Stages of Labor

Stage 1 (Latent, Active, Transition) Stage 2 (Expulsion) Stage 3 (Placental) Stage 4 (Recovery)

brow presentation

The fetal chin is off the chest, and the neck is extended. The fetal brow enters the true pelvis first. The anteroposterior diameter is wider than the biparietal diameter.

Descent

The fetus moves past station 0 during the first and second stages of labor. The patient typically first feels the Ferguson reflex when the fetus is at station +1

Duration of contraction

The length of a contraction, measured from the beginning to its completion

nuchal cord

Umbilical cord around the fetal neck - After the fetal head clears the introitus, the obstetric provider checks the neck for a nuchal cord - in about half of the births in which a nuchal cord occurs, the cord can be easily slipped over the fetus's head and no harm is done to the fetus. This procedure is referred to as "reducing a nuchal cord." - After the birth of the head and reduction of the nuchal cord, if present, the obstetric provider may apply gentle pressure to encourage the birth of the anterior shoulder. The provider then may apply pressure in the opposite direction to facilitate delivery of the posterior shoulder and the rest of the body.

Normal uterine involution

occurs at a predictable rate - One hour after childbirth, the fundus is at the level of the umbilicus. - On the first postpartum day, the fundus is approximately 1 fingerbreadth or 1 cm below the level of the umbilicus. - Thereafter, it descends downward at the rate of 1 fingerbreadth per day until it becomes a pelvic organ again on the 10th day postpartum.

Primary Powers

- Involuntary uterine contractions occur in the muscular upper two thirds of the uterus and apply pressure to the fetus, which in turn applies pressure to the amniotic fluid, the lower portion of the uterus, and the cervix. - In response, the cervix, in the lower portion of the uterus, dilates and effaces, allowing for passage of the products of conception (fetus, placenta, amniotic fluid, membranes, etc.).

Acceleration

- Normal An increase in the FHR from baseline. The change is abrupt, with the increase of bpm peaking in ≤30 s. Return to baseline heart rate is the end of an acceleration. •Before 32 wk of gestation, the acceleration is an increase of ≥10 bpm above baseline lasting ≥10 s but <2 min. •After 32 wk of gestation, the criteria for an acceleration is an increase of ≥15 bpm above baseline lasting ≥15 s but <2 min. •A prolonged acceleration lasts 2-10 min. •An acceleration lasting >10 min is a new baseline heart rate.

Assessment for rupture of membranes

- SROM occurs prior to labor only 8% of the time and typically happens instead when labor is well established - Late in pregnancy the breakdown of the operculum may present as an increase in vaginal fluid. - Leukorrhea or urinary incontinence may be mistaken for SROM. - If a woman presents with suspected SROM with regular contractions or rupture of membranes without contractions (premature rupture of membranes), she will need an exam to discover whether the fluid is amniotic fluid, urine, part of her mucus plug, or vaginal discharge - Assessment of FHR is critical, because there is an increased risk for prolapse of the cord between the fetus and the maternal pelvis with rupture of membranes, particularly if the fetus is not yet engaged in the pelvis. - Further assessment of the fluid itself is needed to detect other complications. - Normal amniotic fluid is clear, whereas fluid that is cloudy or has a foul odor may indicate an intrauterine infection. Fluid stained with meconium may be normal, particularly in postterm pregnancies, but it may also indicate fetal hypoxia in utero

Stage 4: Recovery

- begins with the birth of the placenta and ends after 4 hours or when the mother becomes clinically stable. - The nurse should carefully examine the maternal portion of the placenta. - If parts of the placenta remain attached to the decidua, the uterus will fail to contract completely, which significantly increases the risk of postpartum bleeding. At this time, the obstetric provider repairs any lacerations or episiotomies and the nurse administers any uterotonics and analgesics, per orders.

fetal head diameter

- biparietal diameter approximately 9.25 cm at term - The biparietal diameter is the widest transverse diameter (side to side). - anteroposterior (front to back) length varies according to the flexion of the fetal neck. This dimension is smallest with the fetal neck in flexion. If the neck is less flexed, with the chin off the chest, the anteroposterior diameter increases and the fetus may not be able to pass into the true pelvis (This variation in fetal attitude causes variations in the cephalic presentation)

Assessment

- interview and physical exam is first priority when the woman presents for assessment of labor. - Pertinent info is collected about the duration and frequency of contractions and how long she has been aware of them - She is asked about vaginal discharge and the nature of that discharge (watery, bloody, etc.) - A pain assessment is performed. The woman is asked to describe the intensity of her contractions and to identify any other discomfort. Persistent uterine pain that continues between contractions would be concerning. - The nurse asks about the woman's last food and drink and notes this in the chart. - A physical assessment is done that includes the mother's vital signs and the fetal heart rate (FHR). - Contractions are monitored at the same time as the FHR to obtain information not just about the contractions but also about how well the fetus is tolerating them - A sterile speculum exam may be done by a nurse to evaluate for pooling of fluids suggestive of rupture of membranes as well as for bleeding. - A sterile vaginal exam is done to assess for cervical dilation and effacement and fetal station, presentation, and position - If the fetal position cannot be discerned by vaginal exam, Leopold's maneuvers may be done

Stage 1 (Latent, Active, Transition)

- longest, lasting an average of 12 hours for primigravidas and 8 hours for multigravidas, although the length of labor varies tremendously - begins with the start of regular contractions that cause progressive changes to the cervix and ends when the cervix is dilated 10 cm - the membranes of pregnancy typically rupture spontaneously but may instead be ruptured by the obstetric provider - Maternal cardiac output and pulse increase, whereas peristalsis of the gut and gastric emptying decrease

Internal Fetal Monitoring

- more accurate because fetal or maternal movement or maternal obesity it is not impacted - allows contractions to be assessed for intensity as well as frequency and duration. - invasive. It can be performed only if membranes are ruptured and the cervix is dilated at least a few centimeters. - FHR is monitored via a small spiral electrode that is attached to the presenting part, usually the scalp. - Contractions are monitored with a catheter introduced into the uterus via the vagina - Contractions compress the pressure-sensitive tip of the catheter, which then converts the reading into millimeters of mercury (mm Hg)

Stage 2: Care

- nurse typically checks the FHR every 5 to 15 minutes in the second stage or nurse may assess the FHR after each contraction. - vital signs hourly - The nurse should position the woman for labor according to the woman's preference, as much as possible, and should help her assume and maintain the position, as an advocate for her choice. - Nurses provide support and encouragement and, if the situation warrants it, coaching to push. - Open glottis pushing, which is pushing without the breath being held, is encouraged because it has a positive impact on fetal oxygenation. - The nurse may give the patient sips of water and ice chips, as the patient desires. If the woman passes stool when pushing, which is not uncommon, the nurse should discreetly dispose of it.

Fetal presentation

- refers to the part of the fetus that enters the pelvis first, or the presenting part - a vast majority of infants enter the pelvis head first, which is referred to as a "cephalic presentation" - A "breech" presentation means that the infant's buttocks or feet are descending first into the pelvis - A "shoulder presentation" wherein the shoulder is entering the true pelvis first, is not compatible with a vaginal delivery without correction and occurs in fewer than 1% of women presenting for delivery at term. - three primary variations (cephalic, breech, and shoulder)

fetal attitude

- refers to the position of the fetal body parts in relationship to each other - A typical fetal attitude includes legs flexed at the knees, arms flexed against the chest, back rounded, and the neck flexed with the chin on the chest. This is referred to as "general flexion" (also optimal position for entry into the pelvic inlet) The biparietal diameter of the fetal head is approximately 9.25 cm at term. The biparietal diameter is the widest transverse diameter (side to side). The anteroposterior (front to back) length varies according to the flexion of the fetal neck. This dimension is smallest with the fetal neck in flexion. If the neck is less flexed, with the chin off the chest, the anteroposterior diameter increases and the fetus may not be able to pass into the true pelvis. This variation in fetal attitude causes variations in the cephalic presentation

Stage 3: Placental

- starts when the neonate is born and ends with the birth of the placenta - After the birth of the neonate, the patient's uterus contracts, diminishing the overall surface area of the decidua and the size of the decidua basalis (the area of the decidua underlying the placenta). - This causes the placenta to detach in approximately 5 to 30 minutes. - The uterus continues to contract, and "pinches" closed the open blood vessels in the decidua to prevent maternal hemorrhage. Failure of the uterus to contract, a condition known as uterine atony, is the primary cause for maternal postpartum hemorrhage

true pelvis

- the lower portion of the pelvis between the proximal pelvic inlet and the distal pelvic outlet. (The area between the inlet and the outlet is called the midpelvis)

Molding

- the process by which the sutures and the fontanels (nonbony intersections of the sutures) move such that the shape of the head changes in reference to the birth canal - At times, bones of the skull may even overlap temporarily because of movement of the sutures - The head shape returns to normal within 1 week.

External Fetal Monitoring

- tocotransducer is placed at the fundus of the uterus to detect contractions and an ultrasound transducer placed so as to best detect the FHR - noninvasive, but may limit the patient's mobility. - Wireless monitoring may be available for mothers who wish to ambulate. - The ultrasound transducer may need to be adjusted periodically to account for maternal or fetal movement - Although the external tocotransducer is useful for monitoring the frequency and duration of contractions, it cannot detect the strength of the contraction - Both the tocotransducer and the ultrasound transducer are kept in place with soft elastic bands that wrap around the mother's abdomen. - The nurse should place the ultrasound transducer atop conductive gel, the same gel used with a Doppler ultrasound or an ultrasound used to visually monitor a pregnancy. - The tocotransducer does not require conductive gel. - Both the tocotransducer and ultrasound transducer may be less sensitive if the mother is obese.

Admission to the delivery venue

- typically occurs when cervix is atleast 3 cm dilated and regular contractions are established - admission begins with pt assessment by interview and physical exam

fetal head

- typically the largest and least malleable part of the fetus - Although shoulders are wider, they are also more easily collapsed inward toward the chest, and the chest itself is also malleable - The sutures joining the fetal head are not immobile as they will be later in life, however

descent of the presenting part through the true pelvis

- uses ischial spines as the reference - The level of the ischial spines is referred to as zero station - When a fetus is described as engaged, that means the presenting part has reached zero station - When the presenting part moves beyond the ischial spines, it is described as +1 through +5 station, with +5 indicating crowning (the presenting part visible at the introitus) Negative numbers indicate that the presenting part is still "floating" above station 0 and is not engaged

Secondary Powers

- voluntary, controlled by the laboring woman - the bearing-down movements of the abdomen and diaphragm, which help push out the fetus. - These pushing efforts do not have a direct effect on the uterus but rather increase intraabdominal pressure such that the contractions of the uterus are potentiated - Secondary powers must not be enlisted prior to full dilation, as they do not contribute to effacement and dilation and may cause the cervix to become edematous and open more slowly

Stage 1: Care

-IV line, draw blood for laboratory work, and collect urine for assessment (as indicated) - During first stage of labor vital signs every hour - monitor fetus and contractions every 30 minutes initially and then every 15 minutes as labor progresses into the transition phase - The nurse should encourage the laboring woman to void at least every 2 hours and should assess her bladder periodically, particularly in the late first stage, because a distended bladder may preclude fetal descent - Although frequent vaginal examinations to assess labor progress were once common, nurses now perform fewer such examinations because of the discomfort to the patient, the increased risk of infection, and the limited value of the examination itself The nurse should encourage the patient to participate in activities and positions that make her comfortable during labor. Walking has been shown in several small studies to reduce the duration of the first stage of labor by an hour and a half while decreasing the rate of the cesarean section and epidural use - Women often do best when ambulating with a partner or the nurse present for reassurance and companionship. When the patient is not ambulating, the nurse should remind her to not lie flat on her back to avoid supine hypotension from compression of the vena cava - update patient regularly on status of self and fetus - encourage the patient and partner or family members present to ask questions and should accommodate their requests as is feasible and appropriate. - In transition, the nurse should encourage the patient to breathe deeply during contractions and to rest in between contractions. Some women may relax so deeply between contractions that they develop a sort of amnesia concerning the time between contractions. Other women may find it useful to count their breaths during contractions and to notice at what number the contraction peaks and then starts to release. Some women find it helpful to vocalize during this time; others do not. As transition ends, the nurse should prepare the room, the patient, and the partner for delivery. At this time, the patient is likely to have limited ability to assimilate new information or instructions, so the nurse should keep communication very focused. Also during this time, the nurse should no longer leave the room without a replacement present, because the patient's status may change quickly.

Sterile Vaginal Exams

1. Place a dollop of sterile water-based lubricant on a sterile drape. 2. Don sterile gloves. 3. With your nondominant hand, separate the labia. 4. Lubricate the first two fingers of your dominant hand and insert them into the vagina to locate the cervix. 5. Note: Straightening your arm at the wrist may allow for better access to the cervix. 6. Check the following: ○ Cervical dilation: Sweep your finger from one side of the cervical opening to the other to estimate the distance between the two in centimeters. ○ Cervical effacement: Estimate the length of the cervix. Two centimeters long is 0% effaced, and paper thin is 100% effaced. A cervix that is 1 cm long is 50% effaced. ○ Cervical position: A posterior cervix is oriented so that it "points" toward the pregnant woman's back, whereas an anterior cervix is oriented with its opening toward the vaginal introitus. A mid-position cervix is between these two orientations. A posterior cervix suggests an "unripe" cervix and indicates that labor is unlikely. ○ Station: The station refers to the level of the presenting part in relation to the ischial spines of the pelvis. Station zero means that the presenting part is at the level of the ischial spines and generally means that the fetus is engaged. ○ Presentation: Presentation refers to part of the fetus that is presenting to the maternal pelvis: head (cephalic), buttocks and/or feet (breech), or shoulder. ○ Fetal position: Fetal position refers to the relation of the presenting fetal part to the maternal pelvis (right occiput posterior, for example).

Auscultating FHR

1. locate the fetal back (where fetal heart is best heard) - An experienced nurse can initially assess this location by performing Leopold's maneuvers - A bedside ultrasound may be ordered if the heartbeat cannot be located. - If a Doppler ultrasound is being used, the nurse should place ultrasound gel on the abdomen in the most likely spot for auscultation prior to the use of the transducer. To ensure proper placement, the nurse should find the maternal pulse at the same time as auscultation of the FHR so that the two heart rates, the fetal and the maternal, are not confused. The nurse typically auscultates the FHR before, during, and for 30 to 60 seconds after a contraction to note the baseline heart rate, accelerations, and decelerations. - The rhythm of the fetal heart may be noted as regular or irregular - variability is assessed visually and not by auscultation and cannot be assessed by intermittent auscultation. Assessment of variability can be done only using electronic fetal monitoring. Careful documentation is important with all assessments and interventions, but particularly with intermittent auscultation because, unlike with continuous monitoring, there is no printed record that can be reviewed retrospectively.

411 of labor

4: contractions occurring 4 minutes a part or less (frequency) 1: contractions lasting 1 minute or longer (duration) 1: refers to the previous two criteria having occurred for at least 1 hour

Early deceleration

A benign change, occurring because of pressure on top of the fetal head. It appears as a decrease in FHR simultaneous with a contraction that returns to baseline FHR with the end of the contraction. The nadir (lowest point) of the FHR typically happens at the same time as the apex (peak) of the contraction. Onset to nadir is ≥30 s. - No interventions required

Deceleration

A decrease in the FHR from baseline.

birth plan

A wish list - the nurse is clear about what requests can and can't be accommodated as well as hospital policies that may preclude implementation of aspects of the plan. The nurse may ask the patient to prioritize requests so the nurse will know what is most important to the patient.

psyche

A woman's state of mind; her feelings about herself, her pregnancy, and her surroundings; and her psychological health can all impact her experience of labor and delivery - These factors may also impact the process of labor. - EX: anxiety, stress, and fear can reduce pain tolerance and delay the progress of labor

he four types of true pelves

Android Anthropoid Gynecoid Platypelloid

Cardinal Movements of Labor

As the fetus descends, it rotates so that the orientation of the head in relation to the mother's pelvis is optimal for delivery 1. Engagement 2. Descent 3. Flexion 4. Internal Rotation 5. Extension 6. External Rotation 7. Expulsion

fetal hypoxia

Hypoxia indicates that the low oxygen levels have caused inadequate oxygenation of the fetus at a cellular level, resulting in metabolic acidosis from disproportionately high levels of carbon dioxide in relation to oxygen.

Cervical changes

Labor is marked by regular contractions that contribute to cervical changes, but changes to the cervix happen prior to the onset of regular contractions at the end of pregnancy, as well. Women may be partially effaced and as many as 4 cm dilated for days or even weeks prior to the start of regular contractions.

Signs of impending labor

Labor is not confirmed unless contractions are continuous and progressive and result in dilation and effacement of the cervix. Not reliable, but signs: • Braxton Hicks contractions • Bloody show • Lightening • Nesting • Cervical changes • Gastrointestinal symptoms • Weight loss

Mechanisms of onset of labor

Many factors are involved in triggering labor, including a combination of maternal factors and fetal factors that initiate the beginning of regular contractions and cervical dilation and effacement. Expansion of the uterus is likely involved and may cue hormonal processes that ultimately trigger productive contractions. Additionally, newer research suggests that a cue from fetal proteins in the lungs may play a significant part in the initiation of labor

Single footling breech

One leg presenting.

Weight loss

Some women lose 1 to 3 lb just prior to the onset of labor

GI Symptoms

Some women may have gastrointestinal distress around the time of delivery in the form of diarrhea, heartburn, or nausea.

Baseline heart rate

The FHR between contractions, not including accelerations or decelerations. Baseline heart rate is an average within a 10-min increment for at least 2 min. •Normal baseline: 110-160 bpm •Tachycardia: >160 bpm •Bradycardia: <110 bpm •Tachycardia can be an early sign of fetal hypoxemia. •A FHR <80 bpm or >200 bpm is an emergency. •Persistent bradycardia may cause fetal hypoxia.

Expulsion

The body of the fetus is born

Increment phase of uterine contraction

The buildup phase of the contraction. As the uterus contracts, the sensation becomes more acute. This is the longest phase of a contraction.

Extension

The fetal chin comes off the chest as the maternal tissue is no longer pushing down on the head, and the neck arches as the head is born. At this point the pubic symphysis of the mother is located behind the fetal neck if the fetus is in an occiput-anterior position. This occurs toward the very end of the second stage.

facial presentation

The fetal chin is off the chest, and the neck is sharply extended. The fetal face enters the true pelvis first. The anteroposterior diameter is wider than the biparietal diameter.

Sinciput presentation

The fetal chin is off the chest, and the neck is straight. This is often called the military attitude. The anteroposterior diameter is wider than the biparietal diameter.

Flexion

The fetal head moves so that the chin touches the chest in response to the resistance of maternal tissues, typically in the first stage. This flexion causes the biparietal diameter to be the widest dimension of the presenting part.

Internal rotation

The fetal head rotates to align its widest part with the widest part of the pelvis through which it is passing at any given point, which at the pelvic inlet is lateral but at the pelvic outlet is anterior to posterior. This rotation occurs primarily in the second stage.

External Rotation (restitution)

The fetal head, now born, rotates again as the shoulders move into position to fit through the pelvic outlet (remembering that the broadest dimension of the pelvic outlet is anterior to posterior).

Acme phase of uterine contraction

The peak and shortest but most acute phase of the contraction. Some laboring women may find it helpful to remember that after the acme the contraction releases rapidly.

Decrement phase of uterine contraction

The relaxation of the uterine muscle and the second shortest phase. - During a contraction, blood flow to the placenta is decreased so it is critical that each contraction also has a resting phase, which allows for the perfusion of the placenta by the maternal blood and, in turn, the fetus.

Variability

The sawtooth, irregular pattern of fluctuations in the baseline heart rate, also assessed over a 10-min period and excluding accelerations and decelerations. Assessment is based on amplitude: the difference between the peak and trough of the FHR in bpm. • Absent: No amplitude • Minimal: Amplitude is ≤5 bpm • Moderate: Amplitude is 6-25 bpm • Marked: Amplitude is >25 bpm

Frequency of contractions

The time from the beginning of one contraction to the beginning of the next contraction - time from the beginning of one increment phase to the beginning of the next increment phase

engagement

When the fetal head reaches the level of the ischial spines of the pelvis, typically at station 0, which may occur prior to labor or in early labor

411 Rule

a memory device that women can use when deciding whether they should present for an assessment of labor - a new contraction at least once every 4 minutes that lasts for 1 minute for at least 1 hour. - Some providers may want women to be evaluated when the contractions are less frequent, perhaps every 5 or 6 minutes apart, particularly if the woman lives far away from the birthing venue or has given birth previously. - A woman should contact her obstetric provider immediately if she experiences intense pain—particularly if constant—rupture of membranes, or bleeding.

Sterile speculum exam

assesses for vaginal pooling

Intrapartum period (labor)

begins with the onset of regular uterine contractions and lasts until the expulsion of the placenta

Double footling breech

both feet dangling

frank breech

hips flexed, knees extended

amniotomy

incision into the amnion (rupture of the fetal membrane to induce labor; a special hook is generally used to make the incision) - artificial rupture of the membranes.

Active delivery of placenta

include the use of an uterotonic, such as oxytocin, early cord clamping, and gentle traction (pulling) on the cord. - Although active management reduces the amount of blood loss over what is normal for a vaginal birth (500 mL, on average), it significantly increases the risk of afterpains, the use of analgesia, postpartum vomiting, and return to the hospital after discharge due to bleeding

strength of contraction

intensity of contraction - measured through palpation unless IUPC is in place - In low-risk pregnancies strength is measured by uterine indentability. - To evaluate intensity, a nurse presses her fingertips into the abdomen. The degree of intensity is determined by the firmness of the uterus. • Mild: feels like pushing the tip of your nose • Moderate: feels like pushing your chin • Strong: feels like pushing your forehead

Braxton Hicks contractions

irregular prelabor contractions of the uterus - These contractions are typically felt from midway through the pregnancy onward. Some women may never feel these contractions although it is believed that all women have them. - As labor approaches, they may become more coordinated, with periods of regularity, and it can become more difficult to discern these contractions from true labor

Tachysystole

more than 5 contractions in 10 minutes

gynecoid pelvis

most favorable pelvis for successful labor.

bloody show

mucus streaked with blood from the operculum as the cervix begins to open and change in the approach to labor - if the cervix has been manipulated prior to the appearance of bloody show, it cannot be considered a reliable sign of impending labor.

Passive delivery of placenta

no interventions for delivery of placenta

longitudinal lie

occurs when the long axis of the fetus is parallel to that of the mother (fetal spine to maternal spine side by side)

transverse lie

occurs when the long axis of the fetus is perpendicular to the long axis of the mother (fetal spine lies across the maternal abdomen and crosses her spine

Power in labor

primary or secondary - primary powers of labor are the involuntary uterine contractions and Ferguson reflex (the reflex to push) - secondary power is the voluntary action of pushing itself

passageway

refers to the anatomy of the bony pelvis and the soft tissue of the pelvic floor muscles, introitus (opening to the vagina), and vaginal canal

lightening

refers to the descent of the fetal head into the pelvis. - typically occurs with labor for a multigravida and about 2 weeks prior to the onset of labor for a primigravida

Passenger

refers to the fetus. I Important factors are fetal head, fetal presentation, fetal attitude, fetal lie, and fetal position.

fetal lie

similar to fetal presentation but unlike fetal presentation, which has three primary variations, lie has only two primary variations, longitudinal (or vertical) and transverse (or horizontal). - The longitudinal lie is either a cephalic or breech presentation, and the transverse lie is a shoulder presentation. - Fetuses in an oblique lie that is neither cephalic nor transverse typically convert during labor to one of the two primary lies - Although the fetal lie may only be longitudinal or transverse (or, more rarely, oblique) and refers only to the relation of the fetal spine to the maternal spine, the fetal presentation refers to the specific fetal part

episiotomy

surgical incision of the perineum to enlarge the vagina and so facilitate delivery during childbirth - may be cut midline between the introitus and the rectum or mediolateral - A mediolateral incision starts at the same point in the posterior introitus but is cut at a 45-degree angle.

fetal monitoring

the assessment of the FHR for patterns that may indicate fetal compromise. - A normal pattern (often called reassuring) is associated with positive outcomes for the neonate. - Abnormal patterns (often called nonreassuring) are associated with hypoxemia (low oxygen) of the fetus that may lead to fetal hypoxia - no proven optimal frequency of monitoring Although continuous electronic fetal monitoring is not recommended for routine, low-risk pregnancies and deliveries, it is still used routinely for women who deliver in a hospital setting. Continuous electronic fetal monitoring does not reduce the risk of cerebral palsy or perinatal mortality, as is often thought. It may reduce the rate of neonatal seizures that do not appear to have long-term implications and is well documented to increase the rate of operative deliveries and intervention-related complications Intermittent monitoring, in which the fetus is periodically assessed, should be considered first for low-risk pregnancies and deliveries. However, consistent intermittent monitoring requires one-on-one nursing care, which may not be possible in a given facility.

Intermittent Fetal Monitoring

the checking of the FHR at predetermined intervals and as otherwise indicated - Generally, the nurse should auscultate the FHR every 15 to 30 minutes during the active phase of the first stage and every 5 to 15 minutes in the second stage - The nurse may monitor the FHR with various devices, including a fetoscope, a Doppler ultrasound device, or a Pinard stethoscope

dilation

the drawing up and opening of the cervix from fully closed or only a few centimeters in diameter at the onset of labor to 10 cm in diameter when fully open at the end of the first stage of labor - When the cervix is fully dilated, it can no longer be palpated - In first pregnancies, dilation typically progresses more slowly than effacement, whereas in subsequent pregnancies, effacement and dilation happen more or less simultaneously. Dilation is expressed in centimeters.

Transition phase

the final period of cervical dilation and typically lasts less than 2 hours. (10 cm dilated) - Contractions are strong and close together, a new one starting every 1 to 2 minutes and lasting 40 to 60 seconds each - Women may feel out of control, irritable, uncooperative, exhausted, or dependent. - Some women experience N/V, and perspiration may be noted on the upper lip and forehead - An increase in bloody vaginal discharge is also typical - Delivery preparation begins at this time. If the woman's membranes have not already ruptured the provider will likely perform an amniotomy

vertex presentation

the most common presentation, the fetal attitude is general flexion with the fetal chin on the chest. The largest diameter entering the true pelvis is the biparietal diameter.

Latent phase

the period during which the cervix progressively dilates from 0 to 3 cm - contractions are mild to palpation, enough so that women can typically talk through them. - For some women, this phase is a period of excitement because the long-anticipated birth is finally immanent, whereas for others it may be a period of anxiety - Contractions last approximately 30 to 40 seconds in this phase, and may be as close together as every 3 minutes or as far apart as every 30 minutes. - Contractions may feel like menstrual cramps and may be accompanied by a low backache.

Active phase

the period during which the cervix progressively dilates from 3 to 7 cm. - lasts about 5 hours in a primiparous patient and 2 to 3 hours in a multiparous patient - contractions are moderately strong to palpation and last 30 to 45 seconds. Contractions are more frequent in this phase, coming every 3 to 5 minutes - Women may be more focused than they were during the latent phase and may at times become anxious and restless.

fetal position

the relationship of the presenting part to the maternal pelvis. - In the case of the most common presentation, the vertex presentation, the occiput of the fetal skull is the reference part, meaning that it is the relationship of the occiput to the pelvis that is evaluated -Because the occiput is at the back of the head, fetal position in the case of vertex presentation is indicated from the orientation of facing the fetus's back. In other words, the fetal position is not the direction in which the fetus is facing, but rather the position of the back of the head

False pelvis

the winged portion consisting of the ilia and iliac crest. The front is open and the ilia are joined at the back by the sacrum - Serves to support the internal structures of the abdomen but typically has little to no obstetrical significance

effacement

thinning of the cervix during labor - the thinning and shortening of the cervix from about 2 to 3 cm long and 1 cm thick to effectively absent, with the exception of a small lip - measured in %

Childbirth education

thorough education about normal birth processes, breathing exercises, visualization, hypnosis, and mindfulness

Contraction strength

tocotransducer is useful for monitoring the frequency and duration of contractions, it cannot detect the strength of the contraction. - Contraction strength must still be monitored by abdominal palpation - mild, moderate, strong

Ferguson reflex

urge, push "bearing down reflex" - occurs during second stage of labor - cued when the presenting part of the fetus (usually the head) reaches the pelvic floor

Absent or minimal variability may

• Be caused by fetal sleep or age <32 wk • Indicate supine hypotension, uterine tachysystole, or cord compression • Result from medications

Onset of labor

- Although the mechanisms that initiate labor remain unclear, many physical signs indicate that labor is impending occur. - One familiar sign, the spontaneous rupture of membranes (SROM), actually occurs in only a minority of women. - True labor is marked by contractions with dilation of the cervix.

maternal position

- Gravity can assist in successful labor and delivery. - Contractions are more acute and productive for a woman who is upright and ambulating. - The angle of the pelvis is more conducive to the passage of a fetus when a woman's hips are sharply flexed, as when squatting - Perfusion of the uterus and placenta is superior if a woman is not flat on her back in the lithotomy position - Encouraging women to move into a position they feel is more comfortable, particularly upright or lateral, has been associated with improved outcomes.