Diagnosis and outpatient management of Gitelman syndrome from the first trimester of pregnancy

Abstract

A 32-year-old woman presented with an incidental finding of hypokalaemia on routine bloods at 9 weeks of a second pregnancy, on a background of lifelong salt craving. Her previous pregnancy was uncomplicated. She had no previous significant medical or family history. Venous blood gases showed a hypokalaemic, normochloraemic metabolic alkalosis. Urinary potassium was elevated. Escalating doses of oral supplementation of potassium, magnesium, sodium and potassium-sparing diuretics were required through the course of pregnancy, in response to regular electrolyte monitoring. These were later weaned and completely stopped post partum. Delivery was uneventful with no maternal or neonatal complications. Genetic testing performed post partum showed heterogenous mutation of SCL12A3 gene.

Keywords: fluid electrolyte and acid-base disturbances; pregnancy.

Figure 1

Chart showing antepartum and post-partum trend of potassium and magnesium. Regions shaded blue and orange indicate the normal ranges of potassium and magnesium, respectively. Black arrows indicate points where treatment was initiated or changed. The green dotted line indicates date of delivery.