Prenatal exposure to HMG-CoA reductase inhibitors: effects on fetal and neonatal outcomes.

Abstract Background Use of HMG-CoA reductase inhibitors (statins) is becoming increasingly common. However, a recent study based on a series of cases reported to FDA suggests possible teratogenic effects of statins on embryogenesis, such as limb defects and severe central nervous system anomalies. Methods In a prospective, observational cohort study with a comparison group to examine a fetal toxicity risk of statins, we followed 64 pregnant women taking statins, and 64 comparison group women without exposure to known teratogens. The statin group women were exposed to atorvastatin ( n  = 46), simvastatin ( n  = 9), pravastatin ( n  = 6), or rosuvastatin ( n  = 3) during the first trimester. Results There was no difference in the rate of major malformations between the statin group (1/46 live birth: 2.2%) and the comparison group (1/52 live birth: 1.9%, p  = 0.93). Similarly, there were no statistical differences between the statin and comparison groups in live births (71.9% vs 81.2%), spontaneous abortions (14: 21.9% vs 11: 17.2%), therapeutic abortions (3: 4.7% vs 0: 0%) and stillbirths (1: 1.5% vs 1: 1.6%). Gestational age at birth (38.4 ± 2.8 weeks vs 39.3 ± 1.3 weeks: M ± S.D., p  = 0.04) and birth weight (3.14 ± 0.68 kg vs 3.45 ± 0.42 kg, p  = 0.01) were lower in the statin group. Conclusions The absolute risk of teratogenicity of statins, if any, appears relatively small. A large-scale study is needed to further characterize the teratogenic potential.