Lithium during pregnancy

Lithium during pregnancy: fetal malformations

Lithium slightly increases the risk of heart defects, especially when taken between the first and second months of pregnancy. If possible, it should be suspended during this period.

The results of the largest study to assess the risks to the fetus, pregnancy and delivery of lithium exposure during pregnancy have been published in The Lancet Psychiatry. They show an increased risk of fetal malformations after exposure during the first trimester, but lower than previously thought, and no association with complications of pregnancy or delivery themselves, nor an increased risk of cardiac malformations.

Lithium, mainly used for bipolar disorders, is responsible for malformations mainly affecting the cardiac sphere, with an overrepresentation of Ebstein's disease.

Multicenter international study

This study assessed the risks of malformations and disorders of pregnancy and childbirth in 727 pregnancies exposed to lithium compared to 21,397 unexposed pregnancies, between 1997 and 2015. All women included in the study, who came from six centers in Denmark, Canada, the Netherlands, Sweden, the United Kingdom and the United States, had a mood disorder (bipolar or major depression).

Doubled rehospitalizations, risk of malformations multiplied by 1.5

This study shows that 7.4% of children exposed in utero to lithium during the first trimester have major malformations, compared to 4.3% in the unexposed group. The risk of neonatal rehospitalization within 28 days of birth is almost doubled (27.5% in the exposed group compared to 14.3% in the unexposed group). However, the authors found no association of lithium exposure with pregnancy or delivery complications (preeclampsia, prematurity, gestational diabetes, low birth weight), and no significant difference in heart defects.

“Women should be informed of the risk of malformation in children exposed to lithium in the first trimester, but also of the very high risk of relapse of mental illness during pregnancy and the postpartum period,” said Veerle Berking, senior author of the study and professor of psychiatry, obstetrics, gynecology, and reproductive sciences at the Icahn School of Medicine at Mount Sinai Hospital in New York City. “Given the well-demonstrated efficacy of lithium in reducing relapse in the perinatal period, clinical recommendations are to either continue lithium at a low dose during the first trimester or to resume it after the first trimester or in the immediate postpartum period.”