Hypertensive Disorders of Pregnancy

Gestational hypertension, preeclampsia, eclampsia and HELLP

Maternity

Definitions

Chronic HTN	BP ≥140/90 before pregnancy or before 20 weeks
Gestational HTN	New BP ≥140/90 after 20 weeks, no proteinuria or severe features
Preeclampsia	New BP ≥140/90 after 20 wk (two readings ≥4 h apart) plus proteinuria (≥300 mg/24 h or protein/creatinine ≥0.3) or a severe feature
Eclampsia	New seizure in preeclampsia
HELLP	Hemolysis, Elevated Liver enzymes, Low Platelets

Severe features

BP ≥160 systolic or ≥110 diastolic
Platelets <100,000/µL
Liver enzymes ≥2× normal; severe RUQ or epigastric pain
Creatinine >1.1 mg/dL or doubled
Pulmonary edema
New headache not relieved by medication; visual disturbances

Can start or worsen after birth (up to 6 weeks, mostly in the first week): teach warning signs at discharge.

Prevention: low-dose aspirin Must know

Aspirin 81 mg daily, started at 12–28 weeks (ideally before 16) and continued until delivery, for people at high risk:

High risk (any one): previous preeclampsia, twins/multiples, chronic HTN, diabetes, kidney disease, lupus or antiphospholipid syndrome.
Moderate risk (more than one): first pregnancy, BMI >30, family history, age ≥35, IVF, low income, Black race (reflecting racism-related risk), >10 years since last pregnancy.

Severe-range BP: treat within 30–60 min

If BP stays ≥160 systolic or ≥110 diastolic for 15 min:

Labetalol IV (avoid in asthma, heart block)
Hydralazine IV
Nifedipine immediate-release oral

Goal: lower to ~140–150/90–100, not to normal (protect placental blood flow). Delivery is the cure; betamethasone if birth is likely before 34 weeks.

Magnesium sulfate: prevents seizures (it is not an antihypertensive)

Loading 4–6 g IV over 15–30 min, then 1–2 g/hour by infusion pump on a secondary line.
Usually continued 24 hours after birth.
Therapeutic level ~4–7 mEq/L (4.8–8.4 mg/dL).
Check hourly: deep tendon reflexes, respirations, urine output, LOC, SpO₂, lung sounds. Magnesium is cleared by the kidneys.
Expected: flushing, warmth, drowsiness. It can also slow labor and cause newborn drowsiness and low tone.

Magnesium toxicity Loss of patellar reflexes (first sign) · RR <12 · urine <30 mL/h · SpO₂ falling · slurred speech, extreme weakness · cardiac arrest at very high levels.

Stop the infusion, call the provider, and give the antidote: calcium gluconate 1 g IV (10 mL of 10%) slowly over ~3 min.

Eclamptic seizure

Call for help; stay; note the time.
Turn on her side; protect from injury. Don't restrain; nothing in the mouth.
After: airway, suction, oxygen; magnesium sulfate as ordered.
Assess the fetus (expect bradycardia during the seizure) and watch for abruption.

HELLP

RUQ or epigastric pain, nausea, vomiting, malaise. It can occur with normal-looking BP. Labs: hemolysis (↑ LDH, ↑ bilirubin), ↑ AST/ALT, platelets <100,000. Risks: liver rupture, DIC, abruption. Treatment: stabilize, magnesium, deliver.