Why should ACE inhibitor therapy not be continued during pregnancy?

ACE inhibitors are contraindicated during pregnancy primarily due to their teratogenic effects, meaning they can cause developmental abnormalities in the fetus. Specifically, exposure to ACE inhibitors during the first trimester can lead to congenital malformations, especially affecting the heart and kidneys. Additionally, if taken in the second and third trimesters, these medications can lead to severe fetal complications such as oligohydramnios (low amniotic fluid), fetal renal dysfunction, and even the potential for neonatal death.

Understanding the pregnancy categories of medications is essential. ACE inhibitors fall into category D, which indicates positive evidence of human fetal risk but potential benefits may warrant use in pregnant women despite the risks in certain situations, such as in cases of life-threatening hypertensive emergencies. However, for routine treatment of high blood pressure or heart failure in pregnancy, safer alternatives are typically recommended. This clear understanding of the risks associated with ACE inhibitor therapy forms the basis for their avoidance in pregnant patients, highlighting the critical importance of patient safety and fetal development.