The answer is B. Anticonvulsants such as valproate or carbamazepine can be used as mood stabilizers and have the relatively highest risks of teratogenicity. Valproate is associated with a 6-13% risk of congenital malformation, including neural tube defects. While it is well known by medical students that lithium is associated with Epstein’s anomaly, a cardiac congenital defect, it is important to understand that more recent evidence from prospective trials shows a 2.8% rate of all congenital malformations in patients taking lithium, which is a lower overall risk compared to valproate. Prior retrospective studies had shown rates up to 11%. It is now thought that rates of teratogenicity in patients taking lithium may have been overestimated. First generation antipsychotics like C) Haloperidol are recommended by some experts for the management of severe mania during pregnancy due to their proven efficacy in mood stabilization and low overall risk of teratogenicity. The best studied second generation antipsychotics in pregnancy are olanzapine, risperidone, and D) quetiapine and these show congenital deformation rates that appear to be consistent with general population rates; however, they are not as well studied as FGA’s in pregnancy. Many trials exclude pregnant women for safety and there is a paucity of evidence for effective treatment of mood disorders in pregnancy, making it difficult for physicians to choose the best evidence based care for their pregnant patients.

Publication reference : Yonkers KA et al. Management of bipolar disorder during pregnancy and the postpartum period. Am J Psychiatry. 2004 Apr;161(4):608-20. Review. PubMed PMID: 15056503.
Reference URL: http://ajp.psychiatryonline.org/doi/full/10.1176/appi.ajp.161.4.608