In a review of the risks associated with treating bipolar disorder during pregnancy that was recently published in Current Psychiatry Reports, researchers found that clinical management decisions are made difficult due to a lack of conclusive findings. These difficulties are compounded by inconsistent outcomes for fetal risks from prenatal exposure to mood stabilizers.
Treating bipolar disorder during pregnancy is difficult due to many factors, the primary one being an absence of risk-free options. Bipolar disorder is often treated with polytherapy, but doctors should strive to maintain monotherapy by eliminating those medications that are either highly teratogenic or not essential. Comorbidities are also likely in women with bipolar disorder, including anxiety and substance use. Studies done in 2007 and 2008 showed that women who discontinue medication experience a higher rate of relapse than those who continue (87% vs 37%, and 100% vs 30%, respectively), though these findings showed significant limitations.
When making treatment decisions on antenatal bipolar disorder, doctors should first consider the patient’s preferences. They should also consider gestation time, as fetuses are most vulnerable to teratogenic effects during the first trimester and adaptation syndromes and neonatal withdrawal during the final stage of pregnancy. Other considerations include fetal risk due to medications, the patient’s history of illness and rapid cycling, past episodes of peripartum psychosis, previous response to mood stabilizers, comorbidities, ability to participate in psychotherapy, whether the patient is in a lower-risk subgroup, and the robustness of the patient’s social network.
Although lithium has been the traditional first choice treatment for antenatal bipolar disorder, studies have shown an increased risk for teratogenic defects in infants. Valproate and carbamazepine should be avoided for the same reason. On the other hand, quetiapine and lamotrigine have shown more favorable safety profiles.
Researchers conclude that “some mood stabilizing medications, particularly valproate and carbamazepine, are associated with significant risks of congenital anomalies. The risk of untreated [bipolar disorder] and its high rate of relapse must be weighed against the risks that the medication poses to both the mother and her baby.”
Thomson M, Sharma V. Weighing the risks: the management of bipolar disorder during pregnancy. Curr Psychiatry Rep. 2018;20(3):20.