Lo. Retrospective observational cohort study. This included ♀ with a history of BD or postpartum psychosis, used Li+ during pregnancy, and at least one Li+ serum level during pregnancy was available. Linear and logistic regression models used to investigate the association between weighted average Li+ level and pregnancy duration, birth weight percentiles, preterm birth, and LGA. Subsequent exploratory analyses investigated the role of TSH and T4 as mediators of associations. This evidence concerns the gene CD4 and Behcet disease.