OB PrepU: Chapter 13
During the second stage of labor, a woman is generally a) very aware of activities immediately around her. b) anxious to have people around her. c) no longer in need of a support person. d) turning inward to concentrate on body sensations.
d) turning inward to concentrate on body sensations. Rationale: Second-stage contractions are so unusual that most women are unable to think of things other than what is happening inside their body.
The woman has just delivered a healthy baby boy, but the placenta has not yet delivered. What stage of labor does this scenario represent? a) Third b) Second c) Fourth d) First
a) Third Rationale: Stage 3 begins with the birth of the baby and ends with delivery of the placenta.
Assessment reveals that a woman's cervix is approximately 1 cm in length. The nurse would document this as: a) 100% effaced b) 50% effaced c) 0% effaced d) 75% effaced
b) 50% effaced Rationale: A cervix 1 cm in length is described as 50% effaced. A cervix that measures approximately 2 cm in length is described as 0% effaced. A cervix 1/2 cm in length would be described as 75% effaced. A cervix 0 cm in length would be described as 100% effaced.
There are four essential components of labor. The first is the passageway. It is composed of the bony pelvis and soft tissues. What is one component of the passageway? a) Uterus b) False pelvis c) Cervix d) Perineum
c) Cervix Rationale: The cervix and vagina are soft tissues that form the part of the passageway known as the birth canal.
Question: Place the cardinal movements of labor in the order in which they occur. Engagement, then descent Flexion Internal rotation Extension External rotation Expulsion
Engagement, then descent Flexion Internal rotation Extension External rotation Expulsion
Within the first hour after birth, the nurse would expect to find the woman's fundus: a) At the level of the umbilicus b) One fingerbreadth below the umbilicus c) Between the umbilicus and symphysis pubis d) 2 cm above the umbilicus
a) At the level of the umbilicus Rationale: After birth, the fundus is located midline between the umbilicus and symphysis pubis but then slowly rises to the level of the umbilicus during the first hour after birth. Then the uterus contracts, approximately 1 cm (or fingerbreadth) each day after birth.
A fetus is in the LST position. The nurse interprets this as indicating which of the following as the presenting part? a) Buttocks b) Fetal head c) Shoulder d) Chin
a) Buttocks Rationale: The letter "S" indicates the sacrum or buttocks as the presenting part. The fetal head would be noted by the letter "O," indicating occiput. The fetal chin would be noted by the letter "M," indicating mentum. The fetal shoulder would be noted by the letter "A," indicating the acromion process.
A petite, 5-foot tall, 95-pound woman who is 28 years old is about to deliver her first child and would like to have a vaginal delivery. She has two sisters, both of whom have given birth vaginally. She has gained 25 pounds during a normal, uneventful pregnancy. What type of pelvis would a nurse expect this woman to have upon assessment of the patient? a) Cannot be determined b) Android c) Platypelloid d) Gynecoid
a) Cannot be determined Rationale: Pelvis shape cannot be determined by the information included in the statement. Early in the pregnancy, particularly if a woman has never delivered a baby vaginally, the practitioner may take pelvic measurements to estimate the size of the true pelvis. This helps to determine if the size is adequate for vaginal delivery. However, these measurements do not consistently predict which women will have difficulty delivering vaginally, so most practitioners allow the woman to labor and attempt a vaginal birth.
A client in labor is agitated and nervous about the birth of her child. The nurse explains to the client that fear and anxiety cause the release of certain compounds which can prolong labor. Which of the following is the nurse referring to in the explanation? a) Catecholamines b) Relaxin c) Prostaglandins d) Oxytocin
a) Catecholamines Rationale: Fear and anxiety cause the release of catecholamines, such as norepinephrine and epinephrine which stimulate the adrenergic receptors of the myometrium. This in turn interferes with effective uterine contractions and results in prolonged labor. Estrogen promotes the release of prostaglandins and oxytocin. Relaxin is a hormone that is involved in producing backache by acting on the pelvic joints. Prostaglandins, oxytocin and relaxin are not produced due to fear or anxiety in clients during labor.
The nurse notes that the fetal head is at the vaginal opening and does not regress between contractions. The nurse interprets this finding as which of the following? a) Crowning b) Engagement c) Descent d) Restitution
a) Crowning Rationale: Crowning occurs when the top of the fetal head appears at the vaginal orifice and no longer regresses between contractions. Engagement occurs when the greatest transverse diameter of the head passes through the pelvic inlet. Descent is the downward movement of the fetal head until it is within the pelvic inlet. Restitution or external rotation occurs after the head is born and free of resistance. It untwists, causing the occiput to move about 45 degrees back to its original left or right position.
The initial descent of the fetus into the pelvis to zero station is which one of the cardinal movements of labor? a) Engagement b) Felxion c) Extension d) Expulsion
a) Engagement Rationale: The movement of the fetus into the pelvis from the upper uterus is engagement. This is the first cardinal movement of the fetus in preparation for the spontaneous vaginal delivery. Flexion occurs as the fetus encounters resistance from the soft tissues and muscles of the pelvic floor. Extension is the state in which the fetal head is well flexed with the chin on the chest as the fetus travels through the birth canal. Expulsion occurs after delivery of the anterior and posterior shoulders.
When teaching a group of nursing students about uterine contractions, which of the following would the instructor include as a typical feature? a) Retracting of the lower segment b) Contracting stronger in the lower segment c) Thinning out of the upper segment d) Pulling down of the cervical portion
a) Retracting of the lower segment Rationale: The nurse should identify retraction of the lower segment of the uterus as a feature of typical uterine contractions. As labor progresses the uterine contractions become stronger. The upper segment of the uterus contracts more actively than the lower segment. The lower segment retracts, pulling up the cervix. The upper segment thickens with time and the lower segment thins.
When teaching a group of nursing students about uterine contractions, which of the following would the instructor include as a typical feature? a) Retracting of the lower segment b) Pulling down of the cervical portion c) Thinning out of the upper segment d) Contracting stronger in the lower segment
a) Retracting of the lower segment Rationale: The nurse should identify retraction of the lower segment of the uterus as a feature of typical uterine contractions. As labor progresses the uterine contractions become stronger. The upper segment of the uterus contracts more actively than the lower segment. The lower segment retracts, pulling up the cervix. The upper segment thickens with time and the lower segment thins.
A nurse is teaching a group of nursing students about the role of progesterone in labor. Which of the following should the nurse explain as the function of progesterone? a) Suppresses the uterine irritability throughout pregnancy b) Promotes oxytocin production from the posterior pituitary c) Sensitizes the uterus to effects of oxytocin on the myometrium d) Stimulates smooth muscle contraction in the uterus
a) Suppresses the uterine irritability throughout pregnancy Rationale: The function of progesterone is to suppress uterine irritability throughout pregnancy. The function of estrogen is to promote oxytocin production and to sensitize the uterus to the effects of oxytocin. Prostaglandin, and not progesterone, stimulates the smooth muscle contractions in the uterus.
A nurse is caring for a client in her fourth stage of labor. Which of the following assessments would indicate normal physiologic changes occurring during the fourth stage of labor? Select all that apply. a) Well-contracted uterus in the midline b) Mild uterine cramping and shivering c) Increase in the blood pressure d) Decreased intra-abdominal pressure e) Decrease in the pulse rate
a) Well-contracted uterus in the midline b) Mild uterine cramping and shivering d) Decreased intra-abdominal pressure Rationale: The normal physiologic changes for which a nurse should assess during the fourth stage of labor are a well-contracted uterus in the midline of the abdomen, mild cramping pain and generalized shivering, and decreased intra-abdominal pressure. Hemodynamic changes are due to normal blood loss during delivery, causing moderate tachycardia and a slight fall in the blood pressure during the fourth stage of labor. A fall in the pulse rate and increased blood pressure are not normal findings occurring during the fourth stage of labor.
A nurse is assisting a client who is in the first stage of labor. Which of the following principles should the nurse keep in mind to help make this client's labor and birth as natural as possible? a) Women should be able to move about freely throughout labor b) The support person's access to the client should be limited to prevent the client from becoming overwhelmed c) Routine intravenous fluid should be implemented d) A woman should be allowed to assume a supine position
a) Women should be able to move about freely throughout labor Rationale: Six major concepts that make labor and birth as natural as possible are as follows: 1) labor should begin on its own, not be artificially induced; 2) women should be able to move about freely throughout labor, not be confined to bed; 3) women should receive continuous support from a caring other during labor; 4) no interventions such as intravenous fluid should be used routinely; 5) women should be allowed to assume a nonsupine position such as upright and side-lying for birth; and 6) mother and baby should be housed together after the birth, with unlimited opportunity for breast-feeding.
The first stage of labor is often a time of introspection. In light of this, which of the following would guide your planning of nursing care? a) A woman should be left entirely alone during this period. b) A woman may spend time thinking about what is happening to her. c) No nursing care is needed to be done during this time. d) A woman will rarely speak or laugh during this period.
b) A woman may spend time thinking about what is happening to her. Rationale: Women need a support person with them during all stages of labor.
There are four essential components of labor. The first is the passageway. It is composed of the bony pelvis and soft tissues. What is one component of the passageway? a) Perineum b) Cervix c) False pelvis d) Uterus
b) Cervix Rationale: The cervix and vagina are soft tissues that form the part of the passageway known as the birth canal.
The nurse is measuring a contraction from the beginning of the increment to the end of the decrement for the same contraction, documenting this as which of the following? a) Peak b) Duration c) Frequency d) Intensity
b) Duration Rationale: Duration refers to how long a contraction lasts and is measured from the beginning of the increment to the end of the decrement for the same contraction. Intensity refers to the strength of the contraction determined by manual palpation or measured by an internal intrauterine catheter. Frequency refers to how often contractions occur and is measured from the increment of one contraction to the increment of the next contraction. The peak or acme of a contraction is the highest intensity of a contraction.
The nurse assesses a client in labor and finds that the fetal long axis is longitudinal to the maternal long axis. The nurse documents this finding as which of the following? a) Attitude b) Lie c) Position d) Presentation
b) Lie Rationale: The nurse is assessing fetal lie, the relationship of the fetal long axis to the maternal long axis. When the fetal long axis is longitudinal to the maternal long axis, the lie is said to longitudinal. Presentation is the portion of the fetus that overlies the maternal pelvic inlet. Attitude is the relationship of the different fetal parts to one another. Position is the relationship of the fetal denominator to the different sides of the maternal pelvis.
A 32-year-old woman presents to the labor-and-delivery suite in active labor. She is multigravida, relaxed, and talking with her husband. When examined by the nurse, the fetus is found to be in a cephalic presentation. His occiput is facing toward the front and slightly to the right of the mother's pelvis, and he is exhibiting a flexed attitude. How does the nurse document the position of the fetus? a) LOA b) ROA c) LOP d) ROP
b) ROA Rationale: Document the fetal position in the clinical record using abbreviations (Box 8-1). The first letter describes the side of the maternal pelvis toward which the presenting part is facing ("R" for right and "L" for left). The second letter or abbreviation indicates the reference point ("O" for occiput, "Fr" for frontum, etc.). The last part of the designation specifies whether the presenting part is facing the anterior (A) or the posterior (P) portion of the pelvis, or whether it is in a transverse (T) position.
A nurse is performing a vaginal examination of a woman in the early stages of labor. The woman has been at 2 cm dilated for the past 2 hours, but effacement has progressed steadily. Which of the following should the nurse do to best encourage the client regarding her progress? a) Don't mention anything to the client yet; wait for further dilatation to occur. b) Say, "you are still 2 cm dilated, but the cervix is thinning out nicely." c) Say, "you haven't dilated any further, but hang in there; it will happen eventually." d) Say, "there has been no further dilatation; effacement is progressing."
b) Say, "you are still 2 cm dilated, but the cervix is thinning out nicely." Rationale: Women are anxious to have frequent reports during labor, to reassure them everything is progressing well. If giving a progress report, remember most women are aware of the word dilatation but not effacement. Just saying, "no further dilatation", therefore, is a depressing report. "You're not dilated a lot more, but a lot of thinning is happening and that's just as important" is the same report given in a positive manner.
One of the theories about the onset of labor is the prostaglandin theory. While not being conclusively proven that the action of prostaglandins initiate labor, it is known that prostaglandins do play a role in labor. What is an action of prostaglandins? a) Stimulates uterine muscle to relax b) Softens cervix c) Initiates relaxation of perineum d) Initiates cervical dilation
b) Softens cervix Rationale: The prostaglandin theory is another theory of labor initiation. Prostaglandins influence labor in several ways, which include softening the cervix and stimulating the uterus to contract. However, evidence supporting the theory that prostaglandins are the agents that trigger labor to begin is inconclusive.
A woman is documented on the labor and delivery board to be 7cm dilated. Her family wants to know how long she will be in labor. The nurse should provide which information to the family? a) "She is doing well, in the second stage and it could be anytime now." b) "She is in the transition phase of labor and it will be with in 2 to 3 hours, might be sooner." c) "She is in active labor, she is progressing at this point and we will keep you posted." d) "She is still in early latent labor and has much too long to go to tell when she will deliver."
c) "She is in active labor, she is progressing at this point and we will keep you posted." Rationale: At 7cm dilated, she is considered in Active Phase of labor. There is no science that can predict the length of labor. She is progressing in labor and it is not best to give the family a specific time frame.
A fetus is assessed at 2 cm above the ischial spines. The nurse would document fetal station as: a) +2 b) 0 c) -2 d) +4
c) -2 Rationale: When the presenting part is above the ischial spines, it is noted as a negative station. Since the measurement is 2 cm, the station would be -2. A 0 station indicates that the fetal presenting part is at the level of the ischial spines. Positive stations indicate that the presenting part is below the level of the ischial spines.
The nurse should initially implement which intervention when a nulliparous woman telephones the hospital to report that she is in labor. a) Emphasize that food and fluid should stop or be light b) Tell the woman to stay home until her membranes rupture c) Ask the woman to describe why she believes that she is in labor d) Arrange for the woman to come to the hospital for labor evaluation
c) Ask the woman to describe why she believes that she is in labor Rationale: The nurse needs further information to assist in determining if the woman is in true or false labor. She will need to ask the patient questions to seek further assessment and triage information. Having her wait until membranes rupture may be dangerous, as she may give birth before reaching the hospital. She should continue fluid intake until it is determined whether or not she is in labor. She may be in false labor, and more information should be obtained before she is brought to the hospital.
Which of the following would alert the nurse that the client is in the transition phase of labor? a) Reduction of rectal pressure b) Decrease in the bloody show c) Beginning urge to bear down d) Enthusiasm in the client
c) Beginning urge to bear down Rationale: Starting of the urge to bear down is a feature associated with the transition phase of labor. The transition phase is the last phase of the first stage of labor. In this phase the process of cervical dilatation is completed. During this phase the client experiences an increase in rectal pressure, an increase in the bloody show and an urge to bear down. The contractions are stronger and hence the client feels irritable, restless and nauseous. The client feels enthusiastic during the latent phase and not the transition phase.
Braxton Hicks contractions are termed "practice contractions" and occur throughout pregnancy. When the woman's body is getting ready to go into labor, it begins to show anticipatory signs of impending labor. Among these signs are Braxton Hicks contractions that are more frequent and stronger in intensity. What differentiates Braxton Hicks contractions from true labor? a) Braxton Hicks contractions get closer together with activity b) Braxton Hicks contractions cause "ripening" of the cervix. c) Braxton Hicks contractions usually decrease in intensity with walking d) Braxton Hicks contractions do not last long enough to be true labor
c) Braxton Hicks contractions usually decrease in intensity with walking Rationale: Braxton Hicks contractions occur more frequently and are more noticeable as pregnancy approaches term. These irregular, practice contractions usually decrease in intensity with walking and position changes.
If a fetus is in an ROA position during labor, you would interpret this to mean the fetus is a) Presenting with the face as the presenting part b) In a common breech delivery position c) In a longitudinal lie facing the left posterior d) Facing the right anterior abdominal quadrant
c) In a longitudinal lie facing the left posterior Rationale: ROA (right occiput anterior) means the occiput of the fetal head points toward the mother's right anterior pelvis; the head is the presenting part.
The skull is the most important factor in relation to the labor and birth process. The fetal skull must be small enough to travel through the bony pelvis. What feature of the fetal skull helps to make this passage possible? a) Vertex presentation b) Caput succedaneum c) Molding d) Cephalohematoma
c) Molding Rationale: The cartilage between the bones allows the bones to overlap during labor, a process called molding that elongates the fetal skull thereby reducing the diameter of the head.
The four essential components of labor are known as the "four P's". Which of the four P's involves the pelvis? a) Psyche b) Powers c) Passageway d) Passenger
c) Passageway Rationale: The passageway is one of the 4 P's and involves the pelvis, both bony pelvis and the soft tissues, cervix, and vagina. The "passenger" refers to the fetus. The primary powers are the involuntary contractions of the uterus, whereas the secondary powers come from the maternal abdominal muscles. The psyche refers to the mother's mental state.
When educating a group of nursing students about the theories of onset of labor, the nurse identifies which of the following factors as the possible causes for onset of labor? Select all that apply. a) Increase in the production of progesterone b) Fall in the estrogen at 34-35 weeks of pregnancy c) Prostaglandin production in the myometrium d) Increase in the fetal cortisol levels e) Release of oxytocin by the pituitary
c) Prostaglandin production in the myometrium d) Increase in the fetal cortisol levels e) Release of oxytocin by the pituitary Rationale: The possible causes for the onset of labor include increase in the fetal cortisol levels, release of oxytocin by the posterior pituitary and the production of prostaglandins. Progesterone withdrawal, and not an increase, initiates labor. There is a rise in the estrogen levels at 34-35 weeks of pregnancy. Estrogen stimulates prostaglandin production and also promotes the release of oxytocin.
In preparing for the actual birth, which fetal presentation would a nurse be least likely to find? a) Transverse lie b) Breech c) Shoulder d) Oblique lie
c) Shoulder Rationale: Shoulder presentations are the least likely to occur in less than 0.3 percent of all births. Approximately 97 percent of fetuses are in a cephalic presentation at the end of pregnancy. A longitudinal lie, in which the long axis of the fetus is parallel to the long axis of the mother, is the most common. When the fetus is in a transverse lie, the long axis of the fetus is perpendicular to the long axis of the woman. An oblique lie is in between the two. (
A post delivery CBC has noted an elevated WBC count of 22,000/mm3. Which rationale is accurate regarding the elevated WBC count? a) Abnormal finding and she needs antibiotics b) Might be a false result, recommend re-testing c) This is a normal variation due to stress of labor d) Occurs in patients who have cesarean birth, from the trauma of surgery
c) This is a normal variation due to stress of labor Rationale: An elevation of WBC up to 30,000mm/3 can be normal variation for any woman after delivery. This is related to the stress on her body from labor and delivery. Antibiotics are not indicated as this is a normal response to intense stress. The increase in WBC is not related to cesarean birth. Retesting would be wasteful as it is known that this is a normal response to any stress.
The patient is having a routine prenatal visit and asks the nurse what the childbirth education teacher meant when she used the term zero station. What is the best response by the nurse? a) "This is just a way of determining your progress in labor." b) This indicates that you start labor within the next 24 hours." c) "This means +1 and the baby is entering the true pelvis." d) "The presenting part is at the true pelvis and is engaged."
d) "The presenting part is at the true pelvis and is engaged." Rationale: Zero station is when the fetus is engaged in the pelvis, or has dropped. This is an encouraging sign for the patient. This sign is indicative that labor may be beginning, but there is no set time frame regarding when it will start. Labor has not started yet, and the fetus has not begun to move out of the uterus.
A fetus is assessed at 2 cm above the ischial spines. The nurse would document fetal station as: a) +4 b) +2 c) 0 d) -2
d) -2 Rationale: When the presenting part is above the ischial spines, it is noted as a negative station. Since the measurement is 2 cm, the station would be -2. A 0 station indicates that the fetal presenting part is at the level of the ischial spines. Positive stations indicate that the presenting part is below the level of the ischial spines.
A pregnant woman, multipara, has been in labor for several hours. She cries out that her contractions are getting harder and that she can't do this. The patient is really irritable, nauseated, annoyed, and fearful of being left alone. Considering the client's behavior, the nurse would expect the cervix to be dilated how many centimeters? a) 5-6 b) 0-2 c) 3-5 d) 8-10
d) 8-10 Rationale: The reaction of the patient is indicative of entering or being in the transition phase of labor, stage 1. The dilation would be 8-10 cm. Before that, when dilation is 0-7 cm, the patient has an easier time using positive coping skills.
Which of the following would be least effective in promoting a positive birth outcome for a woman in labor? a) Promoting the woman's feelings of control b) Providing clear information about procedures c) Encouraging the woman to use relaxation techniques d) Allowing the woman time to be alone
d) Allowing the woman time to be alone Rationale: Positive support, not being alone, promotes a positive birth experience. Being alone can increase anxiety and fear, decreasing the woman's ability to cope. Feelings of control promote self-confidence and self-esteem, which in turn help the woman to cope with the challenges of labor. Information about procedures reduces anxiety about the unknown and fosters cooperation and self-confidence in her abilities to deal with labor. Catecholamines are secreted in response to anxiety and fear and can inhibit uterine blood flow and placental perfusion. Relaxation techniques can help to reduce anxiety and fear, in turn decreasing the secretion of catecholamines and ultimately improving the woman's ability to cope with labor.
What term is used to describe the position of the fetal long axis in relation to the long axis of the mother? a) Fetal position b) Fetal presentation c) Fetal attitude d) Fetal lie
d) Fetal lie Rationale: Fetal lie describes the position of the long axis of the fetus in relation to the long axis of the pregnant woman.
The third stage of labor is considered to be expulsion of the placenta. This stage can last anywhere from five to 20 minutes. What is a sign that the placenta is separating from the wall of the uterus? a) Expulsion of blood clots b) Firm fundus c) Shortening of the umbilical cord d) Globular shape to the fundus
d) Globular shape to the fundus Rationale: Signs that indicate the placenta is separating from the uterine wall include a gush of blood, lengthening of the umbilical cord, and a globular shape to the fundus.
A new OB/GYN physician has just finished evaluating her one hundredth patient. In reviewing the documentation from all patients thus far, which types of pelvis would you assume the physician has seen the most and the least? a) Android and platypelloid, respectively b) Gynecoid and android, respectively c) Anthropoid and gynecoid, respectively d) Gynecoid and platypelloid, respectively
d) Gynecoid and platypelloid, respectively Rationale: The gynecoid is the typical female pelvis shape; platypelloid pelvis is the least common type of pelvis in women. Women with anthropoid pelvic shapes are able to deliver normally one third of the time, and are somewhat rare. An android pelvis is similar to a male pelvis, and is seen in 16% of nonwhite women.
Assessment reveals that the fetus of a client in labor is in the vertex presentation. The nurse determines that the presenting part is which of the following? a) Brow b) Buttocks c) Shoulders d) Occiput
d) Occiput Rationale: With a vertex presentation, a type of cephalic presentation, the fetal presenting part is the occiput. The shoulders are the presenting part when the fetus is in a shoulder presentation. The brow or sinciput is the presenting part when a fetus is in a brow presentation. The buttocks are the presenting part when a fetus is in a breech presentation.
A client in labor has been admitted to the labor and birth suite. The nurse assessing her notes that the fetus is in a cephalic presentation. Which of the following should the nurse identify by the term presentation? a) Relation of the different fetal body parts to one another b) Relationship of the presenting part to the maternal pelvis c) Relation of the fetal presenting part to the maternal ischial spine d) Part of the fetal body entering the maternal pelvis first
d) Part of the fetal body entering the maternal pelvis first Rationale: The term presentation is the part of the fetal body that is entering the maternal pelvis first. Relationship of the presenting part to the sides of the maternal pelvis is called the position. Attitude is the term that describes the relation of the different fetal body parts to one another. Relation of the fetal presenting part to maternal ischial spine is termed the station.
When going through the transition phase of labor women often feel out of control. What do women in the transition phase of labor need? a) Their significant other beside them b) Intense nursing care c) Just to be left alone d) Positive reinforcement
d) Positive reinforcement Rationale: Any women, even ones who have had natural childbirth classes, have a difficult time maintaining positive coping strategies during this phase of labor. Many women describe feeling out of control during this phase of labor. A woman in transition needs support, encouragement, and positive reinforcement.
A 32-year-old woman presents to the labor-and-delivery suite in active labor. She is multigravida, relaxed, and talking with her husband. When examined by the nurse, the fetus is found to be in a cephalic presentation. His occiput is facing toward the front and slightly to the right of the mother's pelvis, and he is exhibiting a flexed attitude. How does the nurse document the position of the fetus? a) ROP b) LOP c) LOA d) ROA
d) ROA Rationale: Document the fetal position in the clinical record using abbreviations (Box 8-1). The first letter describes the side of the maternal pelvis toward which the presenting part is facing ("R" for right and "L" for left). The second letter or abbreviation indicates the reference point ("O" for occiput, "Fr" for frontum, etc.). The last part of the designation specifies whether the presenting part is facing the anterior (A) or the posterior (P) portion of the pelvis, or whether it is in a transverse (T) position.