A Rare Cause of Refractory Severe Polyhydramnios: Antenatal Bartter Syndrome

Abstract

Background: Antenatal Bartter syndrome is an autosomal recessive disorder causing severe polyuria that leads to severe polyhydramnios and preterm labor. Prenatal diagnosis of antenatal Bartter syndrome is difficult because the genetic diagnosis can only be confirmed following a clinical diagnosis in infants. Reports of prenatal diagnosis and treatment of antenatal Bartter syndrome are limited. Case Presentation: We present the case of a 33-year-old pregnant woman with refractory polyhydramnios at 31 weeks of gestation. There were no structural anomalies or placental problems on ultrasonography; therefore, antenatal Bartter syndrome was suspected. With repeated amniocentesis and indomethacin therapy, the pregnancy continued to 36 weeks of gestation. The clinical features of the infant and subsequent genetic testing confirmed the diagnosis of antenatal Bartter syndrome. The baby was in good clinical condition at the 3-month follow-up visit. Conclusions: For pregnant women with early onset and refractory severe polyhydramnios without morphological anomalies, antenatal Bartter syndrome should be highly suspected.

Keywords: amniotic fluid; antenatal Bartter syndrome; indomethacin; polyhydramnios.

Figure 1

Ultrasonographic findings at 31 weeks of gestation. (A) Amniotic fluid index was 45.06 cm. (B) Persistent right umbilical vein (arrow) was observed. (C) There were no specific findings in either kidney of the fetus. AFI, amniotic fluid index; LK, left kidney; RK, right kidney.

Figure 2

NKCC2 protein mutation sequencing revealed novel pathogenic mutations in the SLC12A1 gene, which was implicated in antenatal type I Bartter syndrome.