Severe Preeclampsia at 36 Weeks With a Prior Cesarean
33-year-old G2P1 at 36 weeks 4 days by first-trimester ultrasound presents with BP 158/104 mmHg and 158/100 mmHg four hours apart, 3+ proteinuria, platelets 96,000/µL, AST 82 U/L, and creatinine 1.0 mg/dL. She has no headache, visual changes, epigastric pain, or dyspnea. Her baseline blood pressure was 110/70 mmHg, and she has no history of chronic hypertension. The fetal heart tracing is category I and reactive; estimated fetal weight is 2,700 g. Cervix is 1 cm dilated, 50% effaced, station −2. Her prior delivery was cesarean for arrest of descent at 9 cm. She has gestational diabetes controlled on metformin, fasting glucose 92 mg/dL. She asks to go home and be induced at 37 weeks because she feels well. The unit has magnesium sulfate, IV labetalol, and a level III nursery.
1. Does this patient meet criteria for preeclampsia with severe features, and what is the appropriate timing of delivery? Explain the contribution of each abnormal result.
Read the worked answer
She meets criteria for preeclampsia with severe features because the platelet count is 96,000/µL, below the 100,000/µL threshold. The blood pressures of 158/104 and 158/100 mmHg are in the hypertensive range but do not by themselves meet the severe hypertension threshold of at least 160/110 mmHg. The AST of 82 U/L is abnormal but should not be used alone unless it clearly exceeds twice the upper limit of normal for the laboratory. Proteinuria of 3+ establishes the diagnosis of preeclampsia but is not a severity criterion. Because severe features are present at 36 weeks 4 days, delivery is recommended after maternal stabilization; expectant management to 37 weeks is not appropriate. Antenatal corticosteroids are not indicated at this gestational age when delivery is already indicated. She should be admitted, monitored continuously, and prepared for delivery rather than sent home.
2. Outline the immediate management during the first six hours, including magnesium sulfate, antihypertensives, and fetal surveillance.
Read the worked answer
Start magnesium sulfate with a 4–6 g IV loading dose over about 20 minutes, then 1–2 g/hour. Monitor deep tendon reflexes, respiratory rate, and urine output; check magnesium levels if renal function is uncertain. Treat sustained blood pressure of at least 160/110 mmHg with IV labetalol 10–20 mg every 10 minutes or hydralazine 5–10 mg IV, avoiding abrupt drops that could impair uteroplacental perfusion. Obtain continuous fetal monitoring, maternal labs every 6 hours, type and screen, and anesthesia consultation. Use cautious fluid administration, generally around 80 mL/hour, to reduce pulmonary edema risk. Do not give betamethasone for lung maturity at 36 weeks 4 days when delivery is indicated. Notify the neonatal team and prepare blood products if cesarean is planned.
3. How should mode of delivery be counseled given the prior cesarean and unfavorable cervix?
Read the worked answer
A prior cesarean does not mandate repeat cesarean, but this patient has severe preeclampsia, an unfavorable cervix (Bishop score about 3), and a history of arrest of descent. Induction may be prolonged and carries a small but real risk of uterine rupture. Repeat cesarean is a reasonable and often preferred option; trial of labor after cesarean can be offered only with continuous monitoring and immediate operative capability. If trial of labor is chosen, avoid misoprostol for ripening because of rupture risk; a mechanical balloon or carefully administered oxytocin may be considered. If cesarean is chosen, use neuraxial anesthesia when possible, have pediatric support present, and anticipate both hypertension and hemorrhage. Document a shared decision that addresses her preference for a short recovery versus the risks of induction and repeat surgery.