Lithium and pregnancy. I. Report from the Register of Lithium Babies.

We have collected information about 118 children born to mothers who were given lithium treatment during the first trimester of pregnancy. The data show that the risk of teratogenic effects is lower than one might have expected from some of the studies carried out on rats and mice; they do not answer the question of whether or not lithium is teratogenic in man. The data were collected retrospectively and therefore overestimate rather than underestimate the risk of teratogenicity.