Master the board step 3

Obstetrics
Abruptio
Placenta Placenta Previa Vasa Previa Uterine Rupture
Pain Yes No No Yes
Risk factors
Previous abruption
Hypertension
Trauma
Cocaine abuse
Previous previa
Multiparity
Structural
abnormalities (e.g.,
fibroids)
Velamentous insertion
of the umbilical cord
Accessory lobes
Multiple gestation
Previous classic
uterine incision
Myomectomy
(fibroids)
Excessive oxytocin
Advanced maternal
age
Grand multiparity
Diagnosis:
Sonogram
Placenta in normal
position ±
retroplacental
hematoma
Placenta implanted
over the lower
uterine segment
Vessel crossing the
membranes over the
internal cervical os
N/A
Management
1. Emergent c-section: Best choice for
placenta previa or if patient/fetus is
deteriorating.
Immediate c-section
Immediate surgery
and delivery
2. Vaginal delivery if ≥ 36 weeks or continued
bleeding. May be attempted in placenta
previa if placenta is > 2 cm from internal
os.
3. Admit and observe if bleeding has
stopped, vitals and fetal heart rate (FHR)
stable, or < 34 weeks.
Complication
Disseminated
intravascular
coagulation
Placenta accreta/
increta/percreta
→ hysterectomy
Fetal exsanguination
Hysterectomy for
uncontrolled
bleeding
Perinatal Infections
Group B β-Hemolytic Streptococci (GBS)
A 28-year-old woman presents at 36 weeks’ gestation with rupture of membranes.
On examination she is found to have 7 cm cervical dilatation. She received all
of her prenatal care, and her only complication was a course of antibiotics for
asymptomatic bacteriuria. GBS screening was negative. Her first baby was hospitalized
for 10 days after delivery for GBS pneumonia and sepsis. What is the most
appropriate management?
a. Administer intrapartum IV penicillin.
b. Administer intramuscular azithromycin.
c. Rescreen for group B streptococci.
d. Schedule cesarean section.
e. No intervention is needed.
Answer: A. Intrapartum IV penicillin is indicated because the patient’s previous birth
was complicated with neonatal GBS sepsis.
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