Master the board step 3

Master the Boards: USMLE Step 3
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Membranes have not ruptured
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Fetal head is not engaged
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Orientation of the head is not certain
Cesarean Delivery
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The cesarean section rate is approximately 33 percent in the United States
(including both primary and repeat procedures).
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Risks include the following: Increased risk of hemorrhage, infection, visceral
injury (bladder, bowel, ureters), and DVTs.
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Low segment transverse incision: This is the most common procedure. It
can only be performed with longitudinal lie of the fetus.
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Classic vertical incision: Can be performed with any fetal lie. Because of the
increased risk of uterine rupture in subsequent pregnancies, cesarean must
be initiated before labor begins.
When is it the answer?
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Cephalopelvic disproportion (CPD): With failure of progression or arrest
in labor
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Fetal malpresentation: Most commonly preterm breech and nonfrank
breech
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Nonreassuring EFM strip
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Placenta previa (unless placental edge > 2 cm from internal os)
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Infection: Mother who is HIV-positive or has active vaginal herpes
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Uterine scar: Prior myomectomy (fibroid) or prior classic incision c-section
Trial of vaginal birth after cesarean (VBAC) should be attempted in patients
in the absence of c-section indications when the previous cesarean was a low
segment uterine incision. The success rate is 80 percent.
External cephalic version
(ECV) is done to change a
baby from breech or other
non-cephalic presentation
to the cephalic position.
The physician pushes on
the baby through the
mother’s abdomen to
attempt to roll the baby
into position.
External Cephalic Version
When is it the answer?
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Is first attempted in patients with transverse lie or breech presentation.
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The optimum time for external version is 37 weeks’ gestation, and success
rates are 60–70 percent.
Postpartum Hemorrhage
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Uterine atony is the most common cause of excessive postpartum bleeding.
Consider in rapid or protracted labor, chorioamnionitis, medications
(MgSO 4 , halothane), and overdistended uterus. Manage with uterine massage
and uterotonic agents (e.g., oxytocin, methylergonovine, or carboprost).
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