Severe pre-eclampsia as a rare cause of profound hyponatraemia.

Profound hyponatraemia, defined as sodium <125 mmol/L, is a very rare complication of pre-eclampsia (PET) with a relative paucity of cases reported. Pre-eclampsia is a multisystem disorder with a maternal mortality of up to 20%. Hyponatraemia is associated with disease severity, twin pregnancy, advanced maternal age, in vitro fertilisation and HELLP (haemolysis, elevated liver enzymes and low platelets).