Bartter syndrome in two siblings--antenatal and neonatal observations.

Bartter syndrome was diagnosed in two siblings born to healthy unrelated parents. Each pregnancy was complicated by severe polyhydramnios. The first child was treated with indomethacin from the age of then weeks on. At the age of six years he is doing very well: height is 109.9 cm (P3) and weight 17.8 (P3). Studies of the amniotic fluid during the mother's second pregnancy showed high chloride concentrations (112, 117, and 119 mEq/l), normal levels of sodium, potassium, calcium and creatinine and low prostaglandin E2 (5.0-22.3 pg/ml) and F2 alpha (36-71.7 pg/ml) concentrations. Severe chloride and sodium wasting after birth resulted in hypochloremia, hyponatremia and dehydration. Concomitantly an immediate and striking increase in urinary PGE2 excretion from 45 to 1022 pg/ml was observed. Indomethacin therapy had to be stopped after one week when necrotising enterocolitis developed.