THERAPEUTIC DRUGS IN EARLY-PREGNANCY AND CONGENITAL-DEFECTS

In a study of occupation and pregnancy outcome, information was collec ted on certain non-occupational factors including therapeutic drugs ta ken in the first trimester, reported by some 17% of women. A case-refe rent analysis was made of data from pregnancies leading to 787 major ( class I) and 2386 miscellaneous minor (class 2) congenital defects com pared with pregnancies without defects, matched for hospital, maternal age and educational level. In pairs discordant for one of seven drug groups, ratios of positive pairs (case with drug) to negative pairs (r eferent with drug) were for class 1 defects 164:148, relative risk (RR ) 1.11 and for class 2 defects 433:383, RR 1.13. Only anti-infective d rugs showed an increased RR: 1.70(p = 0.06). This was mainly with nerv ous/sensory defects (10:2; RR 5.0, p = 0.04) but no one type of defect or type of drug was identified; the infections for which the drugs we re given might have been responsible. For class 1 defects two pairs we re positive for anti-convulsant drugs and two negative; no increase in risk was found for any specific drugs including doxylamine succinate (Bendectin).