›Maintenance infusion
›1–2 g/hr continuous IV infusion
›Duration: Throughout labor and 24 hours postpartum
›Renal dosing
›Reduce maintenance to 0.5–1 g/hr if creatinine elevated or oliguria
›Monitor more frequently for toxicity
›Toxicity monitoring
›Deep tendon reflexes hourly (loss = early toxicity)
›Hold infusion if reflexes absent
›Respiratory rate every hour (target >12/min)
›Urine output (target >25 mL/hr)
›Serum magnesium level if toxicity suspected
›Therapeutic range 2–3.5 mmol/L
›Loss of reflexes at 5–6 mmol/L
›Respiratory arrest risk at >6 mmol/L
›Antidote at bedside: calcium gluconate 1 g IV over 3 minutes
Non-severe hypertension management
›Oral antihypertensive options
›Labetalol PO
›100–400 mg twice to three times daily
›Titrate to BP target
›Nifedipine extended-release PO
›30–90 mg once daily
›Titrate to effect
›Methyldopa PO
›250–500 mg two to three times daily
›Maximum 3 g/day; sedation is common side effect
›Contraindicated agents in pregnancy
›ACE inhibitors — fetal renal toxicity and Potter sequence
›ARBs — same mechanism as ACE inhibitors
›Direct renin inhibitors — fetal toxicity
›Nitroprusside — fetal cyanide toxicity risk
Corticosteroids for fetal lung maturity
›Betamethasone administration
›Indication: Preeclampsia with anticipated preterm delivery <34 weeks
›12 mg IM every 24 hours for 2 doses
›Full benefit begins 24–48 hours after first dose
›Late preterm protocol (34 0/7 to 36 6/7 weeks)
›Consider betamethasone if delivery anticipated within 7 days
›Reduces late-preterm respiratory morbidity
›Magnesium for fetal neuroprotection
›Indication: Anticipated preterm delivery <32 weeks
›Reduces risk of cerebral palsy (Class I recommendation)
›4 g IV loading dose then 1 g/hr until delivery or 12 hours
Pulmonary edema management
›IV nitroglycerin — preferred agent
›5–10 mcg/min IV infusion
›Titrate by 5 mcg/min every 3–5 minutes
›Maximum 200 mcg/min
›Continuous BP monitoring required
›Furosemide
›20–40 mg IV with caution
›Avoid aggressive diuresis — may impair uteroplacental perfusion
›Indicated for severe pulmonary edema unresponsive to nitroglycerin
›Fluid restriction
›Restrict total fluids to 80 mL/hr or 1 mL/kg/hr
›Preeclampsia patients at risk for iatrogenic pulmonary edema with aggressive IV fluids
Delivery — definitive treatment
›Timing by gestational age
›>=37 weeks — deliver within 24–48 hours of diagnosis regardless of severity
›34–36+6 weeks with severe features — delivery recommended
›24–33+6 weeks without severe features — expectant management possible with close monitoring
›<24 weeks — extremely high maternal complication rate (<=70%); delivery generally recommended
›Mode of delivery
›Vaginal delivery preferred when not contraindicated
›Cesarean delivery for standard obstetric indications, not preeclampsia alone
›Prevention in future pregnancies
›Low-dose aspirin 81 mg/day starting at 12–16 weeks — Grade B recommendation (USPSTF)
›Reduces recurrence risk by approximately 24%