Women can have hypertension before pregnancy or it can be diagnosed in the first 20 weeks (known as chronic hypertension), new onset of hypertension occurring in the second half of pregnancy (gestational hypertension) or new hypertension with features of multi-organ involvement (pre-eclampsia). Although the proportion of women with pregnancy hypertensive disorders overall appears to have stayed reasonably stable, maternal mortality from hypertensive causes has fallen dramatically: less than 1 woman in every million who gives birth now dies from pre- eclampsia. There is consensus that introduction of the 2010 NICE evidence-based guidelines, together with the findings from the confidential enquiry into maternal deaths, has made a pivotal contribution to this fall in maternal mortality. However, hypertension in pregnancy continues to cause substantial maternal morbidity, stillbirths and neonatal deaths, and perinatal morbidity. Women with hypertension in pregnancy are also at increased risk of cardiovascular disease later in life. Variations in care contribute to inequity in adverse outcomes. Adoption and implementation of evidence-based national guidelines have a central role in reducing this variance and improving care and outcomes across the maternity service. Research that has been done since publication of the previous guideline has addressed areas of uncertainty and highlighted where the recommendations can be updated. A surveillance report from 2017 identified new studies in the following areas: management of pregnancy with chronic hypertension management of pregnancy with gestational hypertension management of pregnancy with pre-eclampsia breastfeeding advice and follow-up care at transfer to community care. 