Biochemical examination of mother's urine is useful for prenatal diagnosis of Bartter syndrome.

Bartter syndrome is characterized by renal potassium and chloride loss, hypokalaemia, hypochloraemic metabolic alkalosis and increased plasma renin activity along with elevated angiotensin II and hyperaldosteronism. For diagnosis we conducted biochemical examinations of both amniotic fluid and the mother's urine. Except for potassium, amniotic fluid electrolytes in a mother with a fetus with Bartter syndrome were high. Urinary chloride, sodium and calcium were very low. Thus, the latter parameters may allow prediction of fetal Bartter syndrome during the prenatal period.