Antepartum Care and Fetal Surveillance Flashcards
A patient presents in labor at term. Clinical pelvimetry is performed. She has an oval-shaped pelvis with the AP diameter at the pelvic inlet greater than the transverse diameter. The baby is occiput posterior. The patient most likely has what kind of pelvis?
a. A gynecoid pelvis
b. An android pelvis
c. An anthropoid pelvis
d. A platypelloid pelvis
e. An androgenous pelvis
c. An anthropoid pelvis
The gynecoid pelvis is the classic female pelvis, with a posterior sagittal diameter of the inlet only slightly shorter than the anterior sagittal diameter.
In the anthropoid pelvis, the AP diameter of the inlet is greater than the transverse diameter, resulting in an oval with large sacrosciatic notches, convergent side walls, prominent ischial spines, and a narrow pubic arch.
Pelvic examination is performed in a 34 yo P0101 at 34 weeks’ gestation who is in labor. The patient is noted to be 6 cm dilated, and completely effaced with the fetal nose and mouth palpable. The chin is pointing toward the maternal left hip. This is an example of which of the following?
a. Transverse lie
b. Mentum transverse position
c. Occiput transverse position
d. Brow presentation
e. Vertex presentation
b. Mentum transverse position
The mentum is the point of reference of the fetus when describing the position of the face. Since the mentum is pointing toward the mother’s left hip, the fetal position is described as mentum transverse.
In vertex presentations, the occiput is the point of reference for determining position.
In breech presentations, the sacrum is the point of reference.
You are counseling a 36 yo obese, Hispanic G2P1 at 36 weeks’ gestation about route of delivery. During her first pregnancy, she was induced at 41 weeks’ gestation for mild preeclampsia, and delivered by cesarean as a result of fetal distress during her induction. The patient would like to know if she can have a trial of labor after cesarean (TOLAC) with this pregnancy. Which of the following is the best response to this patient?
a. No, since she has never had a vaginal delivery
b. Yes, but only if she had a low transverse uterine incision.
c. No, because once she has had a cesarean delivery, she must deliver all of her subsequent children by cesarean.
d. Yes, but only if her skin incision was a Pfannensteil.
e. Yes, but she must wait until she goes into labor spontaneously to have a repeat cesarean.
b. Yes, but only if she had a low transverse uterine incision.
The main risk of TOLAC that increases maternal and neonatal morbidity is uterine rupture, the risk of which is impacted significantly by the location of the uterine incision.
A low transverse incision is made transversely through the lower uterine segment, which does not actively contract during labor. Therefore, the risk of rupture is 1%.
A 32 yo poorly controlled diabetic G2P1 is undergoing amniocentesis at 38 weeks for fetal lung maturity prior to having a repeat C-section delivery.
Which of the following lab tests on the amniotic fluid would be indicate that the fetal lungs are mature?
a. L/S ratio of 1.5:1
b. L/S ratio of 2:1
c. Phosphatidylglycerol is present
c. Phosphatidylglycerol is present
L/S ratio in amniotic fluid is close to 1 until about 34 weeks of gestation, when the concentration of lecithin begins to rise. When the L/S ratio is greater than 2, the risk of RDS is slight. However, when fetus is likely to have serious metabolic compromise at birth (e.g., diabetes or sepsis), RDS may develop even with a mature L/S ratio (>2.0).
This may be explained by lack of PG, a phospholipid that enhances surfactant properties. The identification of PG in amniotic fluid provides considerable reassurance (but not absolute guarantee) that RDS will not develop. Contamination of amniotic fluid by blood, meconium, or vaginal secretions will not alter PG measurements.
A healthy 26 yo G1P0 presents for her first OB visit at 10 weeks gestation. She has no significant personal or family medical hx.
When should she have her screening test for gestational diabetes?
between 24-28 weeks
1 hr glucose challenge test should be performed between 24 and 28 weeks’ gestation –> involves administration of a 50 g oral glucose solution followed by a 1 hr venous glucose determination
28 yo G1P0 presents to your office at 24 weeks’ gestation for an unscheduled visit 2/2 R-sided groin pain. She describes the pain as sharp and occurring with movement and exercise. She reports no change in urinary or bowel habits, and no fever or chills. Sitting down and putting her feet up helps alleviate the discomfort. Etiology of pain?
a. Round ligament pain
b. Appendicitis
c. Preterm labor
d. Kidney stone
e. UTI
a. Round ligament pain
This pt reports a classic description of round ligament pain. Each round ligament extends from lateral portion of uterus, travels in a fold of peritoneum downwards to the inguinal canal, inserts in the upper portion of the labium majus.
During pregnancy, these ligaments stretch as the gravid uterus grows farther out of the pelvis, and can therefore cause sharp pain, particularly with sudden movements.
19 yo G1P0 presents to obstetrician’s office for routine OB visit at 32 weeks’ gestation. Her pregnancy has been complicated by gestational diabetes requiring insulin for control. She has been noncompliant with diete and insulin therapy. She has had two prior normal U/S exams at 20 and 28 weeks’ gestation. She has no other significant PMH or SurgHx. During the visit, her fundal height measures 38 cm. Which of the following is the most likely explanation for the discrepancy between fundal height and gestational age?
a. Fetal hydrocephaly
b. Uterine fibroids
c. Polyhydramnios
d. Breech px
e. Undiagnosed twin gestation
c. Polyhydramnios
Uterine fibroids, polyhydramnios, fetal macrosomia, and twin gestation are all plausible explanations. Since this pt has had 2 prior U/S exams, hydrocephaly, fibroids, and twins would have previously been diagnosed.
Polyhydramnios = sign of poor glucose control
Pregnant woman who is 7 weeks from LMP comes in for first prenatal visit. Her previous pregnancy ended in a missed abortion in the first trimester. The pt therefore is very anxious about well-being of this pregnancy. Which of the following modalities allow you to best document fetal cardiac activity?
a. Regular stethoscope
b. Fetoscope
c. Fetal Doppler stethoscope
d. Transvaginal U/S
e. Transabdominal pelvic U/S
d. Transvaginal U/S
Can detect as early as week 5
30 yo G2P1001 presents at 37 weeks for routine OB visit. First pregnancy resulted in vaginal delivery of 9 lb 8 oz baby boy after 30 min of pushing. On doing Leopold maneuvers, you determine that fetus is breech. Vaginal exam demonstrates that cervix is 50% effaced and 2-cm dilated. Presenting breech is high out of the pelvis. Estimated fetal weight is about 7 lb.
Pt reports no contractions. You send pt for U/S –> confirms fetus with a double footling breech px. Normal amt of amniotic fluid present, and head is hyperextended in “stargazer” position. Best next step?
Schedule ECV in next few days
(Note: pt can choose to have elective c-section after 39 wks)
What is the Bishop Score?
Document favorability of cervix for induction
Cervical ripening agent: Cervidil, Cytotec
Labor inducing agent: Pitocin
Your pt reports decreased fetal movement at term. You recommend a modified BPP test. NST in your office was reactive. Next part of the modified BPP is which of the following?
a. CST
b. Amniotic fluid index evaluation
c. U/S assessment of fetal mvmt
d. “ “ of fetal breathing mvmts
e. “ “ of fetal tone
b. Amniotic fluid index evaluation
BPP consists of 5 components: NST + four observations made by real-time U/S
- Fetal breathing mvmts - one or more episodes of fetal movements of 30 sec or more within 30 min
- Fetal mvmt - 3 or more discrete body or limb movements within 30 min
- Fetal tone - one or more episodes of extension of fetal extremity with return to flexion, or opening or closing of hand
- Determination of amniotic fluid volume - a single vertical pocket of amniotic fluid exceeding 2 cm
In modified BPP, only the NST and determination of amniotic fluid volume are assessed. Amniotic fluid volume. reflects fetal urine production, and can be used to evaluate placental function.
