Pregnancy outcomes in women with inadvertent exposure to lovastatin and simvastatin during pregnancy have been examined based on reports submitted to the manufacturer as part of worldwide postmarketing surveillance. There were 134 reports of exposure during pregnancy in which pregnancy outcome was known. Among prospectively followed pregnancies with known outcome, the proportion of normal outcomes was 85%, congenital anomalies 4.0%, spontaneous abortions 8.0%, fetal deaths/stillbirths 1.0%, and miscellaneous adverse outcomes 2.0%. While the number of prospective reports available for evaluation were only sufficient to rule out a three- to fourfold increase in the overall frequency of congenital anomalies, these proportions do not exceed what would be expected in the general population. Based on findings from this interim evaluation, there is no relationship between exposure to therapeutic doses of these agents during pregnancy and the occurrence of adverse pregnancy outcomes.