Aims. There are no published studies on the safety of cefuroxime use during pregnancy. We therefore investigated prospectively the possible teratogenic effect of intrauterine exposure to cefuroxime.Methods. One hundred and six women who received cefuroxime during the first trimester of pregnancy were recruited from three teratogen information centres in Israel. Exposed women were paired for age, smoking habits and alcohol consumption with references being exposed to nonteratogenic antibiotics administered for the same indications. Results. Maternal history, birthweight, gestational age at delivery, rates of live births, spontaneous abortions and fetal distress were comparable among the two groups. Rates of major malformations in the cefuroxime group (3.2%) did not differ from references (2%) (P=0.61, relative risk=1.56, 95% confidence interval 0.27-9.15). There was a significantly higher rate of induced abortions among the cefuroxime exposed women as compared to the references (P=0.04, relative risk=3.33, 95% confidence interval 0.94-11.77). Conclusions. Our data may suggest that exposure to cefuroxime during the first trimester is probably not associated with an increased risk for malformations or spontaneous abortions; however, in light of the small sample size and the broad confidence limits, larger studies are needed to confirm these findings.