Growth until puberty after in utero exposure to coumarins

Anticoagulation with coumarins is an effective therapy during pregnancy. Fe tal exposure to coumarin derivatives during the first trimester, however, i s associated with skeletal anomalies (warfarin or coumarin embryopathy). In formation about long-term effects of prenatal coumarin exposure on the skel etal development is not available. We investigated growth and body proporti ons at school age of children exposed to coumarins in utero. A blind popula tion-based cohort study was conducted on 307 exposed children and 267 non-e xposed controls ages 8-15 years. The exposed cohort was based on a prospect ive registry of coumarin-treated pregnant women. Anthropometric data includ ed height, weight, head circumference, and measurements to evaluate body pr oportions. The mean height of exposed children did not differ from that of the non-exposed children (mean difference 0.01 SD). In addition, no differe nces were found for the proportional measures. As a group, children exposed in the first trimester showed no evidence of growth impairment. Two childr en in this group, however, were born with signs of coumarin embryopathy and one of these displayed a deficit in height at school age. Long-term growth was not, affected by a high cumulative dosage or exposure after the first trimester, We conclude that, when exposure during the first trimester is av oided, coumarin therapy during pregnancy has no demonstrable risk for the c hild's skeletal development, (C) 2000 Wiley-Liss, Inc.