OBJECTIVE: Bartter syndrome is a severe inherited tubulopathy characterized by 
postnatal salt wasting, severe polyuria, dehydration, failure to thrive and 
secondary hyperaldosteronism. Prenatally, the disease is usually discovered 
following the onset of severe polyhydramnios in the second trimester. We studied 
amniotic fluid aldosterone concentration in Bartter syndrome and in controls.
METHODS: Amniotic fluid aldosterone was assayed by radioimmunoassay. We 
undertook a retrospective case-control study based on 36 cases of prenatally 
suspected and postnatally confirmed Bartter syndrome (22 with identified 
mutations): and 72 gestational age matched controls presenting with 
polyhydramnios and 72 without polyhydramnios. Amniotic fluid aldosterone was 
compared between the three groups.
RESULTS: The median amniotic fluid aldosterone concentration in the Bartter 
syndrome group (90 pg/mL) was not different from that in the controls with 
polyhydramnios (90 pg/mL, P = 0.33) or without polyhydramnios (87 pg/mL, 
P = 0.41).
CONCLUSION: Amniotic fluid aldosterone assay cannot be used for prenatal 
diagnosis of Bartter syndrome. © 2015 John Wiley & Sons, Ltd.