Lithium During Pregnancy : Drug Effects and Their Therapeutic Implications

Lithium is used as a primary treatment or augmentation therapy for several psychiatric conditions, such as bipolar depression, mania and unipolar depression. For many patients with bipolar disorder, it is the most effective mood stabiliser.More than half of the patients maintained on lithium are women, and many are of reproductive age. An unknown proportion of women who are receiving lithium maintenance therapy become pregnant, posing numerous clinical issues for the obstetrician, psychiatrist and patient. The specific problems associated with lithium exposure vary during different stages of gestation. The risk of the serious heart defect, Ebstein's anomaly, exists if the drug is taken during weeks 2 to 6 post-conception; risks of fetal/neonatal complications occur if lithium is taken during the second and third trimesters.Given the effects of lithium on the conceptus, potentially safer alternatives may be required. The best case scenario is to counsel fecund women who require lithium to plan pregnancy, allowing for a temporary change in treatment regimen during the period of embryogenesis. If lithium therapy is reinstituted during the second and third trimesters, fetal monitoring for altered renal and endocrine function is important. Lithium requirements usually increase in the third trimester, but should be decreased in the peripartum period to avoid drug toxicity in the neonate and mother. Ultimately, the risk/benefit considerations must guide clinicians and patients in the decision to use lithium during pregnancy.