Unplanned Pregnancies in Adolescents with Bipolar Disorder

To the Editor

We conducted a naturalistic, longitudinal study that prospectively assessed adolescents following their first manic episode. Following a complete description of the study, written informed consent was obtained from each participant’s legal guardian, and adolescents under age 18 also provided written assent. This study was approved by the Institutional Review Boards of the University of Cincinnati and Cincinnati Children’s Hospital Medical Center.

In this study, 83% (19/23) of the adolescent girls aged 15–19 were sexually active, and 30% (7/23) experienced an unplanned pregnancy at least once during the follow-up period (median weeks in study=105; median weeks to first pregnancy=59) while they were still under the age of 20. Additionally, 6 of 8 pregnancies (one of the seven girls became pregnant twice as a teen) resulted in live births. To put this 26% (6/23) birth rate in context, local data on birth rates in the 15–19 age group during the years over which the data were collected (1999–2006) ranged from 0.46–0.54%.¹ The high rate of teen pregnancy we observed is consistent with findings from a larger study (n=249) of bipolar adolescents, which reported a 5% twelve-month prevalence of pregnancy, with higher rates in girls with substance use disorders (20%) than in those without (1%).²

Teens with bipolar disorder require treatment that proactively addresses the risks of unprotected sex as well as factors that may influence decisions about sexual behavior, such as substance use and psychiatric symptoms. Notably, 57% (4/7) of the pregnant teens in our study also had a substance use disorder, and 83% (5/6 with complete data) were experiencing at least subthreshold affective episodes at the time of conception, with 2 girls (33%) meeting full criteria for mania (n=1) or depression (n=1).

The high rates of unplanned pregnancies we observed also suggest that the teratogenicity of psychotropic medications should be considered when prescribing these agents to adolescent girls, as exposure could harm a developing fetus during a critical period of development (i.e., the first trimester), before the pregnancy is discovered. In half (n=4) of the pregnancies in our sample, psychotropic medications were being taken around the time of conception. In each case, the medications were discontinued, but at varying points during the first trimester—almost immediately (n=1), after one month (n=2), and after three months (n=1). Three of the four pregnancies resulted in live births, with no gross anomalies noted in the newborns. The other pregnancy, in which medication was discontinued almost immediately, resulted in a spontaneous abortion after two months. Further study of pregnancy outcomes in these adolescents is needed to understand risks associated with prescribing teratogenic medications to these at-risk teen girls with bipolar disorder.