ACE inhibitors and pregnancy

Last reviewed 01/2018

NICE suggest that clinicians should inform women who take angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) (1):

  • that there is an increased risk of congenital abnormalities if these drugs are taken during pregnancy
  • discuss other antihypertensive treatment with the healthcare professional responsible for managing their hypertension, if they are planning pregnancy

The risks associated with use of ACE inhibitors and ARBs have been described (2):

  • use of angiotensin-converting-enzyme (ACE) inhibitors (and angiotensin receptor blockers) during the second and third trimesters of pregnancy is associated with an increased risk of fetopathy
    • ACE inhibitors are contra-indicated in pregnancy - they may cause oligohydramnios, hypotension, renal failure, and intra-uterine death in the fetus
  • with respect to use of ACEI inhibitors during the first trimester of pregnancy
    • a cohort study was undertaken to assess the association between exposure to ACE inhibitors during the first trimester of pregnancy only and the risk of congenital malformations
      • studied a cohort of 29,507 infants enrolled in Tennessee Medicaid and born between 1985 and 2000 for whom there was no evidence of maternal diabetes
      • infants with only first-trimester exposure to ACE inhibitors had an increased risk of major congenital malformations (risk ratio, 2.71; 95 percent confidence interval, 1.72 to 4.27) as compared with infants who had no exposure to antihypertensive medications
      • infants exposed to ACE inhibitors were at increased risk for malformations of the cardiovascular system (risk ratio, 3.72; 95 percent confidence interval, 1.89 to 7.30) and the central nervous system (risk ratio, 4.39; 95 percent confidence interval, 1.37 to 14.02)
      • in conclusion, exposure to ACE inhibitors during the first trimester cannot be considered safe and should be avoided


  1. NICE (August 2010). Hypertension in pregnancy - the management of hypertensive disorders during pregnancy
  2. Cooper WO et al. Major congenital malformations after first-trimester exposure to ACE inhibitors. N Engl J Med. 2006 Jun 8;354(23):2443-51