 Hypertensive disorders of pregnancy HDP affect 3-15 of pregnancies. Gestational hypertension is new-onset blood pressure BP 14090mmHg after 20 weeks gestation. Pre-eclampsia is gestational hypertension with proteinuria 300mg 24 hours. HDP are the second commonest direct cause of maternal death in the UK and USA, and the leading cause of maternal death in Latin America and the Caribbean. 