Shock, Sepsis & Multisystem · Topic 12 of 14

Pregnancy & Postpartum Emergencies in Adult Acute Care

Special populations · pregnancy & postpartum

Pregnancy & Postpartum Emergencies in Adult Acute Care

Severe-range BP (≥ 160/110) in pregnancy or postpartum is treated within 30–60 minutes, with magnesium for seizures and delivery as the cure.

Key numbers

Preeclampsia: new hypertension after 20 weeks≥ 140/90 after 20 wk

Treat ≥ 160/110 within 30–60 min≥ 160/110 → treat ≤ 60 min

Magnesium 4–6 g IV, then 1–2 g/h4–6 g IV → 1–2 g/h

HELLP: hemolysis, high liver enzymes, low plateletsPlt < 100 × 10⁹/L

Peripartum cardiomyopathy: LVEF < 45% near deliveryLVEF < 45%

01 · DoTreat ≥ 160/110 within 30–60 min

Confirmed severe-range BP (≥ 160 systolic or ≥ 110 diastolic, persisting 15 minutes) in pregnancy or postpartum needs IV labetalol, IV hydralazine or immediate-release oral nifedipine within 30–60 minutes to prevent maternal stroke.

02 · GiveMagnesium 4–6 g IV, then 1–2 g/h

For preeclampsia with severe features or eclampsia, give magnesium sulfate 4–6 g IV over about 20 minutes, then 1–2 g/hour (1 g/h if creatinine > 1.1 mg/dL); continue 12–24 hours postpartum.

03 · Defined byAFE: hypoxia, hypotension, coagulopathy

Amniotic fluid embolism = sudden hypoxia, hypotension (often cardiac arrest) and coagulopathy (DIC) during labor or just after delivery; it is a clinical diagnosis — no laboratory test confirms or excludes it.

Causes & risk factors

Why it happens

Preeclampsia can appear up to 6 weeks postpartumPreeclampsia can first appear after delivery, usually within 4 days but up to 6 weeks; evaluate postpartum hypertension or new headache for it, and treat severe features with 24 hours of IV magnesium.

Presentation

What you'll see

Severe features mean end-organ damageSevere features: platelets < 100 × 10⁹/L, aminotransferases > 2 times normal, persistent RUQ or epigastric pain, creatinine > 1.1 mg/dL or doubled, pulmonary edema, new unrelenting headache, or visual disturbances.

Diagnosis & monitoring

Work-up

Preeclampsia: new hypertension after 20 weeks must knowPreeclampsia = new BP ≥ 140/90 mmHg (2 readings ≥ 4 hours apart) after 20 weeks' gestation plus proteinuria (> 300 mg/24 h or protein/creatinine ≥ 0.3) and/or signs of end-organ damage.

HELLP: hemolysis, high liver enzymes, low plateletsHELLP, a severe form of preeclampsia, = LDH ≥ 600 IU/L, aminotransferases > 2 times normal and platelets < 100 × 10⁹/L; up to 15% have no hypertension or proteinuria.

Magnesium toxicity: calcium gluconate 1 g IVMonitor reflexes, respirations and urine output on magnesium; for loss of reflexes, levels > 10 mEq/L, cardiac dysfunction or hypoventilation, stop the infusion and give calcium gluconate 1 g IV.

Target BP 140–155 / 90–105 mmHgTitrate antihypertensives in severe preeclampsia to systolic 140–155 and diastolic 90–105 mmHg; avoid precipitous drops.

Peripartum cardiomyopathy: LVEF < 45% near deliveryPeripartum cardiomyopathy = heart failure with LVEF < 45% arising in late pregnancy or the months after delivery with no other cause; early symptoms mimic normal pregnancy, so get an echocardiogram.

Do right now

In this order

First moves

Treat ≥ 160/110 within 30–60 min≥ 160/110 → treat ≤ 60 min

→

Magnesium 4–6 g IV, then 1–2 g/h4–6 g IV → 1–2 g/h

→

Delivery is the definitive treatment

Why each step

Treat ≥ 160/110 within 30–60 minConfirmed severe-range BP (≥ 160 systolic or ≥ 110 diastolic, persisting 15 minutes) in pregnancy or postpartum needs IV labetalol, IV hydralazine or immediate-release oral nifedipine within 30–60 minutes to prevent maternal stroke.

Magnesium 4–6 g IV, then 1–2 g/hFor preeclampsia with severe features or eclampsia, give magnesium sulfate 4–6 g IV over about 20 minutes, then 1–2 g/hour (1 g/h if creatinine > 1.1 mg/dL); continue 12–24 hours postpartum.

Delivery is the definitive treatmentDelivery cures preeclampsia: after maternal stabilization, deliver for eclampsia, HELLP, worsening organ function, severe features at ≥ 34 weeks, any preeclampsia at ≥ 37 weeks, or nonreassuring fetal status.

Management

Orders

Magnesium, not benzodiazepines, first for eclampsiaMagnesium sulfate is the anticonvulsant for eclamptic seizures and prevents recurrence; give IV lorazepam or diazepam only for seizures that continue despite magnesium.

PPCM in pregnancy: avoid ACE inhibitors, ARBs, ARNITreat PPCM as heart failure but, before delivery, avoid ACE inhibitors, ARBs, sacubitril/valsartan and MRAs; use a beta-blocker (metoprolol, not atenolol), hydralazine with nitrates and loop diuretics, then full therapy postpartum.

Anticoagulate PPCM when LVEF < 35%Anticoagulate PPCM when LVEF < 35% or LV thrombus is present; bromocriptine (2.5 mg twice daily for 2 weeks, then daily for 6 weeks) may be added, always with anticoagulation.

AFE: oxygenate, pressors and inotropes, transfuse earlyManage amniotic fluid embolism with immediate high-quality CPR if arrested, intubation and oxygenation, vasopressors and inotropes, no excessive fluid, and early massive transfusion with cryoprecipitate for coagulopathy.

Maternal arrest: displace uterus, hysterotomy at 4 minIn maternal cardiac arrest, displace the uterus manually to the left during CPR; if there is no return of circulation, perform resuscitative hysterotomy at 4 minutes, with delivery by 5 minutes.

Heparins, not warfarin, for anticoagulation in pregnancyWarfarin crosses the placenta and is teratogenic, especially at 6–12 weeks; LMWH and unfractionated heparin do not cross the placenta and are the anticoagulants of choice in pregnancy.

Labetalol IV: 20, then 40, then 80 mgFirst-line doses for severe-range BP: labetalol 20 mg IV, then 40 and 80 mg every 10 minutes; hydralazine 5–10 mg IV every 20 minutes; or immediate-release nifedipine 10 mg orally, repeated at 20-minute intervals.

Red flags & don'ts

Avoid harm

Avoid ACE inhibitors and ARBs in pregnancy avoidACE inhibitors, ARBs and mineralocorticoid receptor antagonists are contraindicated in pregnancy; labetalol, nifedipine and methyldopa are the first-line antihypertensives.

The rules

Know these

Do not withhold needed CT in pregnancyUltrasound and MRI are preferred when they answer the question, but radiography and CT deliver far less radiation than doses that harm the fetus and must not be withheld when needed for diagnosis.

More detail

Reference

Show 5 reference facts

If successive doses of first-line agents fail to control severe hypertension, obtain emergent anesthesiology, maternal-fetal medicine or critical care consultation for second-line therapy.

HELLP develops in 10–20% of patients with severe preeclampsia or eclampsia; preeclampsia also risks placental abruption, pulmonary edema, AKI, hepatic rupture and cerebral hemorrhage.

Low-dose aspirin 81 mg daily, started at 12–28 weeks (ideally before 16) and continued to delivery, prevents preeclampsia in patients with high-risk factors.

About half of PPCM patients recover LV function within 6 months; LVEF < 30% or LV end-diastolic diameter > 60 mm at diagnosis predicts poor outcome, and recurrence risk in later pregnancies is high.

Amniotic fluid embolism (2–6 per 100,000 pregnancies; mortality 20–90%) is not a mechanical embolus but an inflammatory response to fetal antigens that causes right ventricular failure and DIC.

Pearl

A pregnant or postpartum patient with BP ≥ 160/110 is treated within the hour — the danger is maternal stroke.

Sources · Merck Manual Professional — Preeclampsia and Eclampsia (updated Nov 2025; cites ACOG Practice Bulletin 222) · ACOG Committee Opinion No. 767: Emergent therapy for acute-onset, severe hypertension during pregnancy and the postpartum period. Obstet Gynecol 2019;133:e174–e180 (summary page) · Hypertensive Disorders of Pregnancy. Methodist DeBakey Cardiovasc J 2024;20(2) (table of ACOG doses: labetalol 20/40/80 mg IV q10 min, hydralazine 5–10 mg IV q20 min, nifedipine IR 10 mg; magnesium 4–6 g load, 1–2 g/h; severe BP persisting 15 min) · Merck Manual Professional — Amniotic Fluid Embolism (updated Apr 2025) · Society for Maternal-Fetal Medicine, Pacheco LD et al. Amniotic fluid embolism: diagnosis and management. Am J Obstet Gynecol 2016;215(2):B16–B24 (Europe PMC abstract) · Cardiovascular disease in pregnancy: when two hearts beat as one. Diagnostics 2025;15:2921 (compares 2025 ESC and 2020 AHA recommendations) · ACOG Committee Opinion No. 723: Guidelines for diagnostic imaging during pregnancy and lactation. Obstet Gynecol 2017;130:e210–e216 (Europe PMC abstract) · Merck Manual Professional — Dilated Cardiomyopathy (peripartum cardiomyopathy: ACE inhibitors, ARB, ARNI, MRA, SGLT2i potentially teratogenic) · Evaluation and Management of Hypertensive Disorders of Pregnancy. Kidney360 2023;4(10) (severe BP ≥ 160/110 confirmed within 15 minutes, treat within 30–60 minutes; Table 5 acute dosing) · Starter sheet built from the verified AGACNP fact map (facts reviewed 2026-10-15).