RAAS inhibitors in pregnancy, breastfeeding and women of childbearing potential: a review of national and international clinical practice guidelines.

Globally prevalent conditions such as hypertension, heart failure, ischaemic heart disease (IHD) and chronic kidney disease (CKD) are frequently and effectively treated with blockers of the renin-angiotensin-aldosterone system (RAAS) as a first line treatment in the UK and worldwide. RAAS blockers are prohibited in pregnancy due to their adverse fetal effects. We reviewed clinical guidelines from the National Institute of Health and Care Excellence (NICE) on the management of cardiovascular and kidney disease with RAAS blockers in pregnancy, with other UK, European and American guidance as comparators. Whilst guidelines agree on the strict avoidance of RAAS blockers in pregnancy, nuanced considerations regarding prescription in women of childbearing potential, contraception, timing of RAAS blocker withdrawal and breastfeeding are not consistently addressed in clinical guidelines. We call for consistent wording and more explicit advice on RAAS blocker prescription in women of childbearing potential, in pregnancy and in the postpartum period in future iterations of clinical guidelines.