Who / when
- Any pregnant woman with BP 140/90 or higher, and any woman with a convulsion in pregnancy or up to 6 weeks after birth.
- Measure BP at every antenatal and postnatal contact. Pre-eclampsia may have no symptoms; swollen feet alone are not a reliable sign.
- Treat any convulsion in pregnancy as eclampsia until proven otherwise; some women with eclampsia have normal BP.
Red flags: refer now
- Convulsion, or unconscious.
- BP 160/110 or higher.
- Severe or worsening headache, blurred vision.
- Pain in the upper abdomen (epigastric or right upper), nausea or vomiting.
- Breathlessness (fluid on the lungs), passing little urine.
- Brisk reflexes or clonus.
Act nowAny one of these with raised BP after 20 weeks is severe pre-eclampsia: give magnesium sulfate, lower severe BP and transfer urgently. Never leave the woman alone.
Assess
- Measure BP sitting, rested; repeat. Two readings of 140/90 or more four hours apart confirm hypertension.
- Before 20 weeks: likely chronic hypertension. After 20 weeks: gestational hypertension or pre-eclampsia.
- Urine protein on a clean-catch midstream sample: 2+ or more on dipstick is significant (UTI, severe anaemia and blood can give false positives).
- Ask about headache, vision, abdominal pain, breathing, urine output, fetal movements. Check reflexes, chest, fetal heart.
- If a laboratory is available: platelets, liver enzymes, creatinine. A bedside clotting test if severe.
Classify
Adapted from WHO Managing complications in pregnancy and childbirth (2017), Table S-12. If any severe sign is present, diagnose severe pre-eclampsia even without proteinuria.| Findings (after 20 weeks unless stated) | Classify as | Action |
|---|
| Convulsions with BP 140/90 or more | Eclampsia | Magnesium sulfate, control BP, urgent transfer; birth within 12 hours of the fit |
| BP 160/110 or more or any red flag symptom, with proteinuria 2+ | Severe pre-eclampsia | Magnesium sulfate, control BP, urgent transfer for birth |
| BP 140 to 159 / 90 to 109, proteinuria 2+, no severe features | Pre-eclampsia (mild) | Refer for assessment; review twice weekly; induction at 37 weeks |
| BP 140 to 159 / 90 to 109, no proteinuria, no features | Gestational hypertension | BP, urine and fetus weekly; induce at term if no labour |
| BP 140/90 or more before 20 weeks | Chronic hypertension | Treat (see below); watch for superimposed pre-eclampsia |
Treat
Magnesium sulfate: the anticonvulsant of choice
Fit again after 15 minutes: 2 g of 50% IV over 5 minutes. Cannot give the full regimen? Give the loading dose and transfer immediately. Doses from WHO MCPC (2017).| Regimen | Loading dose | Maintenance (24 h after birth or last fit, whichever is later) |
|---|
| Intramuscular | 4 g of 20% IV over 5 minutes, then 10 g of 50% deep IM: 5 g in each buttock with 1 mL 2% lidocaine | 5 g of 50% deep IM every 4 hours, alternate buttocks |
| Intravenous | 4 g IV | 1 g per hour by infusion (pump if available) |
Before each repeat dose check: breathing 16 per minute or more, knee reflexes present, urine 30 mL per hour or more over 4 hours. If not, delay or stop. Respiratory arrest: ventilate and give calcium gluconate 1 g (10 mL of 10%) IV slowly over 3 minutes.
Lower BP of 160/110 or more (choose by experience, cost and availability)
- Nifedipine immediate-release 5 to 10 mg by mouth, repeat after 30 minutes if needed (maximum 30 mg in the acute phase).
- Labetalol 200 mg by mouth, repeat after 1 hour (not with asthma or heart failure); or hydralazine or labetalol IV where trained.
- Methyldopa 750 mg by mouth, repeat after 3 hours (maximum 3 g in 24 hours).
- Keep BP above the lower limit of normal: do not drop it too far.
Non-severe hypertension (140 to 159 / 90 to 109): WHO 2020 says offer treatment where there is good antenatal follow-up; oral methyldopa or a beta-blocker are reasonable choices. Never ACE inhibitors, ARBs or diuretics in pregnancy. No ergometrine for women with high BP.
Follow-up
- Gestational hypertension: BP, urine protein and fetal well-being every week.
- Mild pre-eclampsia managed as an outpatient: twice a week, with danger-sign advice.
- After birth: continue antihypertensives if she was on them; treat severe postpartum hypertension. BP often peaks towards the end of the first week, after discharge, so check it at every postnatal contact.
Counsel
- Prevention: low-dose aspirin 75 mg daily, started before 20 weeks (ideally from 12 weeks), for women at high risk: previous pre-eclampsia, diabetes, chronic hypertension, kidney or autoimmune disease, twins.
- Calcium 1.5 to 2.0 g a day where diets are low in calcium.
- Bed rest, salt restriction, vitamins C, D or E and diuretics do not prevent pre-eclampsia.
- Know the danger signs; plan to give birth in a facility; keep transport ready.
Your blood pressure is high, which can be dangerous for you and the baby. If you get a bad headache, blurred vision, pain high in your belly, trouble breathing or a fit, come straight away, day or night.
When to refer
- Urgently, after the first doses: eclampsia, severe pre-eclampsia, BP 160/110 or more.
- Pre-eclampsia of any severity, for assessment and a plan for birth.
- Gestational hypertension that is worsening, or with poor fetal growth or reduced movements.
- Postpartum BP 160/110 or more, or new symptoms after birth.
- Send the woman with a health worker, the referral note and the doses given.
Sources
World Health Organization. WHO recommendations for prevention and treatment of pre-eclampsia and eclampsia. 2011. World Health Organization. WHO recommendations on drug treatment for non-severe hypertension in pregnancy. 2020. World Health Organization. Managing complications in pregnancy and childbirth: a guide for midwives and doctors, 2nd edition. 2017. World Health Organization. WHO recommendations on antenatal care for a positive pregnancy experience. 2016.