Postpartum Hypertension

Postpartum hypertension is blood pressure of 140/90 mmHg or more after delivery, up to 6 weeks postpartum. It includes persistence of gestational hypertension or preeclampsia and new onset disease, and blood pressure peaks on days 3 to 6. It matters because stroke, eclampsia and heart failure occur after discharge, and it is a common cause of readmission.

• Risk factors: preeclampsia, chronic hypertension, obesity, kidney disease, caesarean section, NSAID use, fluid overload.
• Many women with postpartum preeclampsia had normal blood pressure in pregnancy.
• Most settle within 6 weeks.

Women may have headache, visual change, epigastric pain, breathlessness, swelling or none. Some present with a seizure or pulmonary oedema.

• Blood pressure 140/90 mmHg or more on two readings.
• New severe headache after delivery.
• Differential diagnosis: postpartum preeclampsia, eclampsia, cerebral venous thrombosis, posterior reversible encephalopathy syndrome, peripartum cardiomyopathy, post-dural puncture headache, pain, drug effect (NSAIDs, ergometrine).
• Complications: eclampsia, stroke, pulmonary oedema, heart failure, acute kidney injury, HELLP syndrome, readmission, later chronic hypertension.

The diagnosis is confirmed by repeated readings with a search for preeclampsia and other causes.

• Blood pressure on two readings 4 hours apart (or one severe reading); weight, oedema, reflexes, chest examination.
• Full blood count, platelets, creatinine, liver enzymes, lactate dehydrogenase, urine protein to creatinine ratio.
• ECG and echocardiography if breathless or oedematous; brain CT or MRI with venography for persistent headache, seizures or focal deficit.
• Medication review for NSAIDs, ergometrine, decongestants and steroids.

The principle is to treat blood pressure at 150/100 mmHg or more, give magnesium sulphate for severe features and use drugs compatible with breastfeeding.

• Supportive: rest; stop NSAIDs; reduce salt intake; daily weight; home blood pressure twice daily; admit for 160/110 mmHg or more, symptoms or abnormal blood tests.
• Pharmacological: nifedipine modified release 30 to 60 mg oral once daily (maximum 120 mg) or enalapril 5 mg oral once daily increased to 20 mg (maximum 40 mg) or labetalol 200 mg oral every 8 to 12 hours (maximum 2.4 g daily) for blood pressure 150/100 mmHg or more, aiming below 140/90 mmHg; for 160/110 mmHg or more give labetalol 20 mg IV over 2 minutes then 40 mg, 80 mg and 80 mg at 10 minute intervals (maximum 220 mg) or nifedipine immediate release 10 mg oral repeated once after 30 minutes or hydralazine 5 mg IV then 5 to 10 mg every 20 to 30 minutes (maximum 20 mg); magnesium sulphate 4 g IV over 20 minutes then 1 g per hour for 24 hours for severe features or seizure; furosemide 20 mg oral daily for 5 days for fluid overload or pulmonary oedema; paracetamol 1 g oral 6-hourly (maximum 4 g in 24 hours) for pain; enoxaparin 40 mg subcutaneous daily for 6 weeks if risk factors for thrombosis.
• Procedures: brain imaging for seizures or persistent headache; none otherwise.
• Special groups: breastfeeding is compatible with nifedipine, enalapril, labetalol and methyldopa; enalapril is avoided if another pregnancy is planned soon and is started only with reliable contraception; asthma uses nifedipine instead of labetalol; kidney disease reduces magnesium sulphate to 0.5 g per hour with level monitoring.
• Red flags: blood pressure 160/110 mmHg or more, severe headache, visual change, chest pain, breathlessness, seizure, oliguria.
• Follow-up: blood pressure daily for 5 days, then at 2 weeks and 6 weeks; reduce drugs slowly when below 130/80 mmHg for 1 week; urine protein and kidney function at 6 weeks; yearly blood pressure.