Psychiatry Expert Witness Discusses Birth Defect Risks of Lithium

This case involves the newborn of a thirty-year-old woman with bipolar disorder. For three years, the woman had been under the care of a psychiatrist for her bipolar disorder. The woman’s psychiatric condition was being treated with lithium, a mood stabilizer. She was not told not to get pregnant while on lithium. The woman was a late registrant during pregnancy, who established care when she was twenty-two weeks gestation. Her gynecologist was concerned that she continued taking her lithium during pregnancy. Inspection of the fetal heart during prenatal testing revealed a potential defect. The woman stated that she still wanted to continue with the pregnancy. The woman was referred to another psychiatrist who prescribed her a different mood stabilizer for her bipolar disorder. After the child was delivered, she had a positive S3 and S4 heart sound, systolic ejection murmur, and showed evidence of heart hypertrophy. An echocardiogram was performed which revealed the diagnosis of Ebstein’s anomaly. The child required immediate therapy with numerous pharmacological agents. Later in childhood, the child required surgery to correct her heart condition because the heart could not tolerate strenuous physical activity.

Question(s) For Expert Witness

1. Did the initial psychiatrist practice the standard of care when prescribing lithium to this woman, and what should have been done to prevent the development of Ebstein’s anomaly in this child?

Expert Witness Response

There is great debate over prescribing certain medications to women during pregnancy. Many medications used to treat psychiatric conditions are associated with birth defects. This psychiatrist failed to communicate the risk of Ebstein’s anomaly in the developing fetus when prescribing lithium. Routine echocardiography should be performed during pregnancy when lithium is used during therapy. Additionally, using an alternative medication such as lamotrigine is appropriate. Ebstein’s anomaly is a heart condition characterized by downward displacement of the tricuspid valve toward the apex of the right ventricle and atrialization of the right ventricle. The medical consequences of this anomaly include risks for developing cyanosis, thromboembolic disease, arrhythmias, endocarditis, and heart failure. To address these concerns, patients are usually initiated on an anti-arrhythmic like amiodarone. If atrial fibrillation develops, an anticoagulant should be administered. Surgery is indicated if patients have limited exercise capacity, increased heart size, cyanosis, severe tricuspid regurgitation, and transient ischemic attack or stroke. When prescribing lithium, it is imperative that the physician inquires about plans of becoming pregnancy. Contraception and barrier methods should be discussed if the woman is sexually active.