A Population‐based Case‐Control Teratological Study of Three Parenteral Penicillins G

The purpose of the study was to check the human teratogenic potential of three penicillins G: parenteral treatments with benzylpenicillin, benzylpenicillin‐procaine, and benzylpenicillin + benzylpenicillin‐procaine during pregnancy in the population‐based dataset of the Hungarian Case‐Control Surveillance of Congenital Abnormalities, 1980–1996. Of 38,151 pregnant women who had babies without any defects (population control group), 303 (0.8%) were treated with penicillin G. Of 22,865 pregnant women who had offspring with congenital abnormalities, 236 (1.O%) were treated with penicillin G (crude OR with 95% CI = 1.3, 1.1–1.5). Of 812 mothers who deliveried babies affected with Down syndrome (patient controls), 15 (1.8%) had penicillin G treatment, and this rate exceeded significantly the figure of both the case and population control groups. This finding needs further studies. The case‐control pair analysis did not indicate a teratogenic risk of three parenteral penicillin G treatments during the second‐third months of gestation, i.e., in the critical period for major congenital abnormalities. The lower use of penicillins G was explained mainly by recall bias in the population control group. Thus, parenteral penicillin G treatments during pregnancy do not present a detectable teratogenic risk to the fetus.