[Congenital Intermittent Third-degree Atrioventricular Block Associated with Retinoid Exposure in Pregnancy]

The retinoid acitretin, which has been approved as an effective therapy for severe keratinization disorders, is highly teratogenic, and exposure in the first trimester of pregnancy is associated with the risk of miscarriage and various malformations, including congenital heart defects. Cardiac conduction system disorders have not been described so far.

A 24-year-old woman was treated with acitretin for dyskeratosis follicularis until pregnancy was diagnosed at 12 weeks of gestation. The female infant was born after 35 weeks gestation by cesarean section because of intermittent fetal bradycardia. The baby was vigorous at birth (Apgar 9, 10, 10 at 1, 5 and 10 min) but displayed intermittent third-degree atrioventricular block. A search for maternal autoantibodies and viral infections gave negative findings.

The spectrum of disorders caused by intrauterine retinoid exposure appears to include atrioventricular conduction failure.