What is the best course of action for a 30-something year old primigravida (first-time pregnant woman) at 37 weeks gestational age (GA) with severe hypertension, irritated on examination, and absent end diastolic flow?

Immediate Cesarean Section is Indicated

This patient requires immediate cesarean delivery given the combination of severe hypertension (160/100 mmHg) at 37 weeks gestation with absent end-diastolic flow (AEDF) in the umbilical artery. 1

Rationale for Cesarean Section Over Other Options

Why Not Amniotomy or Induction of Labor?

• Cesarean section should be considered for pregnancies with fetal growth restriction complicated by absent or reversed end-diastolic velocity, based on the entire clinical scenario 2
• At 37 weeks with AEDF, the fetus has already reached the recommended delivery window (33-34 weeks for AEDF), making immediate delivery mandatory rather than attempting labor induction 1, 3
• The presence of severe hypertension (≥160/100 mmHg) combined with AEDF indicates severe placental insufficiency and fetal compromise, requiring rapid delivery 1
• Vaginal delivery through induction would delay definitive treatment and expose both mother and fetus to prolonged risk during a potentially lengthy labor process 1

Critical Clinical Features Driving This Decision

Maternal factors:

• Blood pressure of 160/100 mmHg meets criteria for severe hypertension requiring immediate treatment and delivery consideration 1, 4
• "Irritated on examination" may indicate evolving severe features of preeclampsia (neurological symptoms) 4
• All women with severe pre-eclampsia should be delivered promptly, either vaginally or by caesarean section, regardless of gestational age 1

Fetal factors:

• Absent end-diastolic flow at 37 weeks is well beyond the recommended delivery timing of 33-34 weeks 1, 3
• Fundal height of 35 weeks at 37 weeks gestation suggests fetal growth restriction 1
• The combination of AEDF with growth restriction carries significant risk of perinatal mortality (historically 63.6% with reversed flow, though lower with absent flow) 5

Immediate Pre-Delivery Management

Blood pressure control:

• Initiate immediate antihypertensive treatment for BP ≥160/110 mmHg lasting >15 minutes 4, 6
• First-line agents: IV labetalol or oral nifedipine to achieve target BP <160 mmHg systolic and DBP around 85-100 mmHg 1, 4, 7
• Continue antihypertensive treatment during cesarean section to keep SBP <160 mmHg and DBP <110 mmHg 1

Magnesium sulfate:

• Administer magnesium sulfate for seizure prophylaxis given severe hypertension with potential neurological symptoms ("irritated") 4

Antenatal corticosteroids:

• Not indicated at 37 weeks gestation as fetal lung maturity is expected 1, 3

Critical Pitfalls to Avoid

• Delaying delivery beyond 34 weeks in cases of AEDF increases the risk of adverse outcomes - this patient is already at 37 weeks 3
• Attempting vaginal delivery when rapid delivery is needed due to maternal deterioration and evidence of placental insufficiency with fetal compromise 4
• Failing to control blood pressure before cesarean section, which increases risk of stroke and other maternal complications 4
• Not administering magnesium sulfate when severe hypertension is present with neurological signs or symptoms 4

Mode of Delivery Considerations

• Cesarean section is likely when absent or reversed end-diastolic flow umbilical artery Doppler waveforms are present 1
• The cervical exam showing only 1 cm dilatation in a primigravida makes successful vaginal delivery unlikely in a timely manner 1
• The clinical scenario demands rapid delivery given the combination of severe maternal hypertension and advanced fetal compromise (AEDF at 37 weeks) 1, 4