What is a significant risk of using ACE inhibitors during the first and second trimesters of pregnancy?

The significant risk associated with the use of ACE inhibitors during the first and second trimesters of pregnancy is renal failure with anuria and oligohydramnios in 50% of cases. ACE inhibitors, which are commonly prescribed for hypertension and certain heart conditions, interfere with the renin-angiotensin-aldosterone system. This interference can lead to impaired renal function and reduced amniotic fluid levels.

During the first and second trimesters, the developing fetus relies on proper kidney function to regulate amniotic fluid volume. When an ACE inhibitor is used, it can lead to fetal renal dysfunction, significantly increasing the risk of oligohydramnios (low amniotic fluid). Consequently, as amniotic fluid decreases, this can result in severe complications, including pulmonary hypoplasia, deformities, and other long-term issues related to fetal development and health.

Other options present risks associated with pregnancy, but they do not specifically relate to the severe complications caused by ACE inhibitors. Increased risk of fetal macrosomia, development of gestational diabetes, and a higher chance of ectopic pregnancy do not correlate with the specific adverse renal effects that ACE inhibitors can have during the early stages of pregnancy.