Primary aldosteronism in pregnancy.

We describe a case of primary aldosteronism secondary to bilateral adrenal hyperplasia in three subsequent pregnancies. The disease was diagnosed soon after the first pregnancy, which ended in a miscarriage, and was treated pharmacologically with spironolactone. Because spironolactone is contraindicated in pregnancy, while the hypotensive effects of methyldopa, hydralazine, labetalol, diazoxide and nifedipine were unsatisfactory, in the second (since week 14) and third (since week 6) pregnancy, she received amiloride. This agent, administered at a daily dose of 10-15 mg, effectively controlled blood pressure, reversed hypokalaemia, and led to an increase in plasma renin activity. The course of both pregnancies was uneventful and ultrasonography performed during each visit revealed normal foetal development without growth retardation. Both pregnancies ended in giving birth to healthy children. Our report shows that each case of treatment-resistant hypertension in pregnancy requires assessment for the presence of primary aldosteronism, and that amiloride seems to be a safe and effective agent in the non-surgical treatment of this disorder in pregnant women with primary aldosteronism.