Diagnosis and management of antenatal bartter syndrome-experience from an Australian tertiary neonatal unit.

Brief Introduction: Bartter syndrome (BS) is a rare inherited tubulopathy defined (Bartter et al. 1962) as the association of hypokalemia with metabolic alkalosis, hyperaldosteronism with normal blood pressure and hyperplasia of the juxtaglomerular apparatus (figure 1). There is marked variation in age of onset, clinical presentation and severity of symptoms in accordance with different genetic abnormalities identified and the different transporter channels that they affect (table 1). The incidence of antenatal variant of BS varies between 1 to 2 cases per 100,000 live births per year. Early recognition and management of the antenatal form of BS is critical to patient survival. However, the low incidence and the presence of other morbidities, especially in premature infants, may impede timely diagnosis. Material(s) and Method(s): The aim of this study was to describe the presenting features, management and short-term outcomes of infants diagnosed with antenatal Bartter syndrome (aBS). The study was a retrospective case series of all infants who were admitted to a tertiary neonatal intensive care unit, and who were diagnosed with antenatal onset of Bartter syndrome between January 2007 and December 2013. Clinical Cases or Summary Results: Six cases of antenatal onset of Bartter syndrome were identified (table 2). All infants had an antenatal history of unexplained polyhydramnios and premature labour and delivery. Amnioreduction was performed in four cases. Fluid chloride analysis was performed in only one of these cases and the level was significantly elevated. The median gestation of delivery was 32 weeks (range 25 to 34 weeks). There was a male predominance of 5:1 and all had weights appropriate for gestational age. All infants had>10% weight loss within the first 48 hours of life due to polyuria, and required fluid replacement therapy with saline infusion as high as 40 millilitres/kilogram/hour in the first few weeks of life. All except one exhibited significant e