Lithium Toxicity in a Pregnant Woman

Abstract

Lithium is recommended in bipolar disorder and can be accompanied by significant toxicity in pregnant women. A 25-year-old single-gestation pregnant woman (28 weeks) was referred with suspicion of lithium toxicity. Serum lithium was 2.1 meq/L. Despite conservative therapy with intravenous fluids, lithium concentration increased to 5.0 meq/L 6 hr after admission mandating an emergent haemodialysis during which foetal heart rate decreased to 90 bpm. The gynaecologist ordered termination of pregnancy while the mother was still on haemodialysis. Caesarean section was carried out, but the born baby had an apgar of 2 and died. Autopsy findings of the foetus revealed a cord blood lithium concentration of 4.8 mEq/L with no physical abnormalities. Although the foetus had the signs/symptoms of distress, continuation of haemodialysis could probably have saved it as it saved its mother's life. In lithium toxicity in a pregnant woman, it is reasonable to continue haemodialysis even with the signs and symptoms of foetal distress. In similar situations, emergency haemodialysis instead of immediate caesarean section should be considered.