RESUMEN
UNLABELLED: The effect of 51 antimicrobial drugs was evaluated for the reduction of preterm birth. STUDY DESIGN: Newborn infants without birth defects were selected from the population-based large data set of the Hungarian Case-Control Surveillance of Congenital Abnormalities, 1980-1996, for the study. Medically recorded gestational age and the proportion of preterm birth were the primary outcomes of the study and newborn infants born to mothers with or without a given antimicrobial drug were compared. RESULTS: The use of 51 antimicrobial drugs in the mothers of 38 151 newborn infants including at least ten pregnant women was evaluated. Only two: ampicillin and clotrimazole showed an obvious preterm birth preventive effect, mainly after the use during the first trimester of pregnancy. CONCLUSIONS: Our findings suggest that ampicillin and particularly clotrimazole may be effective for the reduction of preterm birth associated with infectious diseases of pregnant women.