Prognosis and outcome of pregnancies exposed to renin-angiotensin system blockers.

Objective: To study pregnancy outcomes and fetal renal prognosis markers in cases of exposure to renin-angiotensin system blockers.

Methods: We conducted a retrospective study of a series of 21 patients exposed to blockers of the renin-angiotensin system during pregnancy. Two markers were prenatally studied, fetal serum β2-microglobulin and amniotic fluid volume. Poor renal prognosis evaluation was based on postnatal glomerular filtration rate or on the presence of renal histologic lesions.

Results: Of the 21 fetuses, only one had a normal postnatal renal function at birth (oligohydramnios regression and normal β2-microglobulin). All fetuses with persistent oligohydramnios or β2-microglobulin ≥ 5 mg/L presented an adverse renal outcome.

Conclusions: Exposure to renin-angiotensin system blockers complicated by oligohydramnios is associated with a very poor outcome. We propose a prenatal management based on amniotic fluid volume monitoring and fetal serum β2-microglobulin. However, our preliminary results have to be confirmed by a larger study.