The New England Journal of Medicine had a recent article about how the use of angiotensin-converting–enzyme (ACE) inhibitors by women in their first trimester of pregnancy can result in major congenital malformations.

Previously it had been shown that the use of ACE inhibitors during the 2nd and 3rd trimesters of pregnancy could result in an increased chance of fetopathy.

ACE inhibitors are used to treat hypertension and cardiovascular disorders. They work by lowering arteriolar resistance and increasing venous capacitance; increasing cardiac output and cardiac index, stroke work and volume, lowering renovascular resistance, and leading to increased natriuresis (from Wikipedia)

The study looked at 29,507 babies born between 1985 and 2000 . Of these 209 were exposed to ACE inhibitors in just the first trimester and 202 were exposed to other antihypertensive drugs in just the first trimester. The rest were not exposed to any medications for hypertension during gestation.

Based on vital records and hospitalization claims while they were under a year old it was determined the ones exposed to the drugs during the 1st trimester had a greater chance of major congenital malformations. The authors of the study suggest that ‘exposure to ACE inhibitors during the first trimester cannot be considered safe and should be avoided’. Reference: New England Journal of Medicine Volume 354:2443-2451 June 8, 2006 Number 23

(Technorati Tags: pregnancy, ACE inhibitors, trimester, hypertension, NEJM)