Hypertension (HTN) in Pregnancy

🔍 When to Suspect

A new blood pressure reading ≥140/90 mmHg in a pregnant woman (gestational hypertension if after 20 weeks) or worsening of pre-existing hypertension

From the full topic in The Ocean Library: Hypertension (HTN) in Pregnancy

🧭 When to suspect

Hypertension complicates up to 1 in 10 pregnancies and remains a leading cause of maternal and perinatal morbidity. Define hypertension in pregnancy as a sustained blood pressure (BP) ≥ 140/90 mmHg; severe hypertension is ≥ 160/110 mmHg. Three patterns matter in primary care: chronic hypertension (present before pregnancy or before 20 weeks, or already on antihypertensives), gestational hypertension (new after 20 weeks, without significant proteinuria), and pre-eclampsia (new hypertension after 20 weeks with proteinuria and/or maternal organ dysfunction).

The pivotal shift to remember is that pre-eclampsia no longer requires proteinuria. New hypertension after 20 weeks plus maternal organ dysfunction (kidney, liver, neurological or haematological) or fetal growth restriction is sufficient to diagnose it. A clean urine dipstick therefore never excludes pre-eclampsia.

The primary-care role is threefold: risk-stratify early and offer aspirin prophylaxis from 12 weeks to those who qualify; recognise and urgently refer new hypertension or pre-eclampsia symptoms after 20 weeks; and provide safe pharmacological management and postnatal follow-up. New hypertension after 20 weeks is assessed in secondary care (maternity), not in primary care alone.

Pattern	Definition / timing	Key primary-care action
Chronic hypertension	BP ≥ 140/90 mmHg before pregnancy or before 20 weeks (or already on treatment)	Pre-conception/early review: stop unsafe drugs, switch to a pregnancy-safe agent, start aspirin from 12 weeks, refer to specialist
Gestational hypertension	New BP ≥ 140/90 mmHg after 20 weeks, without significant proteinuria	Same-day maternity (secondary-care) assessment; watch closely for evolution into pre-eclampsia
Pre-eclampsia	New BP ≥ 140/90 mmHg after 20 weeks plus proteinuria and/or maternal organ dysfunction (renal, hepatic, neurological, haematological) or fetal growth restriction	Urgent maternity assessment / admission – the diagnosis that must never be missed
Severe hypertension (any pattern)	BP ≥ 160/110 mmHg	Emergency admission for rapid control, whatever the underlying pattern

Source: NICE NG133

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