design-preeclampsia-prevention-protocol

Design Preeclampsia Prevention Protocol

Use risk stratification, low-dose aspirin, and monitoring to reduce preeclampsia risk and detect it early.

Why This Is Best Practice

Adopted by: ACOG, USPSTF, NICE, WHO — all recommend low-dose aspirin for high-risk patients based on Class A evidence. Impact: Low-dose aspirin (81 mg/day) initiated before 16 weeks reduces preterm preeclampsia by 62% (Roberge meta-analysis, AJOG 2017, 45 RCTs, n=20,909). Preeclampsia is responsible for 76,000 maternal deaths and 500,000 fetal deaths annually (WHO 2011). Why best: Preeclampsia has no cure except delivery. Prevention in high-risk women and early detection in all women are the only levers.

Steps

1. Risk stratify at first prenatal visit:
   • High risk (1+ factor): prior preeclampsia, chronic hypertension, DM1/DM2, kidney disease, autoimmune (SLE/APS), multifetal gestation
   • Moderate risk (2+ factors): nulliparity, BMI >30, family history, age >35, low socioeconomic status, inter-pregnancy interval >10 years
2. Prescribe low-dose aspirin if high-risk or 2+ moderate risk factors:
   • Dose: 81 mg/day (not 325 mg)
   • Start: 12–16 weeks (before 16 weeks for maximum benefit)
   • Continue through 36 weeks gestation
3. Calcium supplementation: 1,000–1,500 mg/day if dietary intake is low — reduces preeclampsia risk in low-calcium populations (WHO 2016).
4. BP monitoring at every prenatal visit: thresholds:
   • Severe: ≥160/110 mmHg — treat within 30–60 minutes, do not wait
   • Elevated: 140–159/90–109 mmHg → increase visit frequency, 24-hour urine protein, labs
5. Home BP monitoring (high-risk patients):
   • Upper arm cuff (wrist cuffs less accurate in pregnancy)
   • Log readings at rest; alert provider if consistently ≥140/90
6. Educate on warning signs — see design-pregnancy-complication-action-plan for full list.

Rules

• Aspirin must start before 16 weeks to be effective — starting after 20 weeks has minimal benefit.
• Stop aspirin at 36 weeks (reduces bleeding risk at delivery); earlier if placenta previa confirmed.
• Never treat severe hypertension (≥160/110) in pregnancy with "watchful waiting" — acute treatment prevents stroke.

Examples

High-risk patient (prior preeclampsia): Start aspirin 81 mg at 12 weeks; home BP monitoring 2×/day from 20 weeks; 24-hour urine protein at 28 and 34 weeks. Moderate risk (nullipara, BMI 32): Aspirin 81 mg if second moderate risk factor present; increase calcium to 1,200 mg/day.

Common Mistakes

• Using 325 mg aspirin — only 81 mg is studied; 325 mg increases bleeding risk without additional benefit.
• Starting aspirin after 20 weeks and expecting full effect — the window is before 16 weeks.
• Missing the headache/visual change warning signs — these can precede eclamptic seizure by hours.

Health Disclaimer: Preeclampsia risk assessment and aspirin prescribing require medical evaluation. Hypertension in pregnancy is a medical emergency. Contact your provider immediately for BP ≥140/90 or any warning symptoms.