BACKGROUND: Sibutramine is a drug used for the medical treatment of obesity. No data are available on sibutramine use in pregnancy. We report the fetal outcomes of two pregnant women exposed to sibutramine. CASES: The first woman was exposed to 10 mg/day of sibutramine during gestational weeks 4-6. The second woman was exposed to 10 mg/day of sibutramine during gestational weeks 5-8. At weeks 37 and 39, they delivered healthy infants. CONCLUSIONS: To our knowledge, this is the first report of sibutramine exposure in pregnancy. These cases may contribute to the knowledge about sibutramine use during pregnancy. (C) 2004 Wiley-Liss, Inc.