Risk-Benefit assessment of infant exposure to lithium through breast milk: a systematic review of the literature

The continuation of lithium while breastfeeding is a controversial topic, and clinical recommendations vary. A systematic review was completed of available data on lithium and breastfeeding to determine the degree of lithium exposure through breast milk and assess the potential risk to the infant. Databases, including PubMed MEDLINE, Embase, PsycINFO, Web of Science, Scopus, and Cochrane CENTRAL Register of Controlled Trials databases, were searched for articles on lithium and breastfeeding from the start dates of the databases through December 2018. Articles were included if the report included at least one maternal serum/plasma and/or breast milk lithium concentration and one infant serum/plasma lithium concentration. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Twelve articles, all case reports, were selected for inclusion out of 441 articles that were found and 230 that were reviewed from the search. Data are limited on the safety of lithium continuation while breastfeeding. Among the adverse effects reported, it is difficult to differentiate poor outcomes from factors affecting infant health, concomitant medications, and gestational lithium exposure. Recommendations on whether to continue lithium while breastfeeding must be personalized to the individual woman and her infant.