While we have data on the use of lithium use during pregnancy with regard to risk for congenital malformations, there is much less information on the long-term effects of lithium on neurodevelopment. A recent study from the Perinatal Center of the Leiden University Medical Center provides some reassuring data on the long-term effects of lithium exposure.
Women with bipolar disorder or history of postpartum psychosis are at high risk for postpartum psychosis; appropriate interventions significantly decrease this risk.
In this essay published in the Journal of the American Medical Association, Dr. Helen Kim (an alumna of the CWMH) discusses the challenges of treating women with severe psychiatric illness during pregnancy:
Bipolar disorder (types I and II) affect up to 5% of the population in the United States. As the onset of this condition typically occurs during or before the reproductive years, the management of bipolar disorder in women is often complicated by pregnancy. There are concerns regarding fetal exposure to medication, the impact of untreated maternal illness, and data demonstrating that women are at increased risk for relapse during the postpartum period.
After last week’s post, we received several comments regarding the use of mood stabilizers in breastfeeding women, specifically asking which is safer: lithium or lamotrigine.
Driven by concerns regarding fetal exposure to psychotropic medications, many women with psychiatric illness attempt to discontinue their pharmacologic treatment during pregnancy; however, recent studies indicate that this approach may not be appropriate for all women. Dr. Adele Viguera and her colleagues at the Center for Women’s Mental Health have reported that among pregnant women with bipolar disorder, relapse rates were very high (58%) in women who discontinued maintenance treatment with lithium during pregnancy (Viguera et al 2000). Given this risk of recurrent illness, many women may consider continuing lithium treatment during pregnancy. While the teratogenic effects of first trimester exposure to lithium have been well studied, data on the long-term outcome of children exposed to lithium during pregnancy are sparse. At the 61st Annual Meeting of the Society of Biological Psychiatry in Toronto, Dr. Viguera presented preliminary data on the neurobehavioral outcomes of children exposed to lithium in utero.
It is clear that women with bipolar disorder are at high risk for relapse during the immediate postpartum period (Viguera 2000). There is evidence that the resumption of lithium prior to or within 24-48 hours of delivery can significantly reduce the risk of postpartum illness (Cohen 1995). While this intervention is the current standard of care for this high risk population, women have historically been instructed to avoid breastfeeding while taking lithium based on early reports suggesting high levels of lithium in the breast milk and several cases of lithium toxicity in nursing infants (Schou 1973). While the American Academy of Pediatrics guidelines are less restrictive in their current recommendation, they do urge caution. However, systematic studies regarding the levels of exposure to lithium in nursing infants and the potential risks of this exposure have been lacking.
For women with bipolar disorder who are planning a pregnancy, it is common practice to discontinue mood stabilizers prior to attempts to conceive, since the mood stabilizers most commonly used to treat bipolar disorder (lithium, valproic acid, and carbamazepine) all carry some risk of birth defect. The problem with this approach is that, after discontinuation of maintenance treatment, a woman is at very high risk for relapse. The longer it takes to get pregnant and the longer she remains off medication, the greater is her risk for having recurrent illness.
