Lithium is the standard treatment for bipolar disorder. It has long been contra-indicated during pregnancy because of its teratogenicity, especially regarding cardiac anomalies. More recent epidemiological studies show that the teratogenic risk of lithium has been overestimated in the past. When caring for a pregnant bipolar woman, physicians should consider the risk of fetal exposure to a mood stabilizer but also the risk of relapse if the treatment is interrupted. We have conducted a literature review on this subject. In the second part of the article, we have looked at the authors' recommendations about possible administration of lithium during pregnancy, timing of prophylaxis and precautions to minimize risks.