Foetal kidney maldevelopment in maternal use of angiotensin II type I receptor antagonists.

We report renal lesions observed in a foetus exposed throughout pregnancy to angiotensin II type I (AT 1) receptor antagonists. The mother suffered from essential hypertension and was treated with Cozaar (losartan 50 mg). Autopsy examination of the foetus revealed severe renal lesions, including tubular dysgenesis, hypertrophy of the endothelial and medial cells lining the arterial and arteriolar walls, hyperplasia of the juxtaglomerular apparatus and poorly developed vasa recta. Similar lesions have already been observed in foetuses of women treated with angiotensin-converting enzyme antagonists and also in foetuses and neonates of animals undergoing experimental blockade of the renin-angiotensin system. The purpose of this report is to describe structural lesions observed in the kidneys, and, particularly, vascular lesions. Our results suggest that the use of AT 1 receptor antagonists during pregnancy may have a severe deleterious effect on kidney development in the foetus.