Effect of mebendazole threapy in pregnancy on birth outcome

Abstract

OBJECTIVES : A prospective, unmatched, case-control study was done to assess the safety of mebendazole threapy in pregnancy, a hitherto uninvestigated factor. DESIGN : All women delivering in the University Obstetrics Unit of the Ragama Teaching Hospital between May 1996 and, March 1997 were administered a questionnaire soon after delivery. Details of the birth and the baby were recorded; suspected defects were confirmed by a paediatrician. The incidence of congenital defects in babies of mothers who had taken mebendazole during the pregnancy was compared with the incidence among those who had not taken an anthelmintic (controls). Data analysis was done using Epi Info 6.03. RESULTS : Of 3688 women, 73.5% had taken mebendazole, 24.8% had not taken any any anthelmintic , 1.1% had taken an anthelmintic but could not identify it and 0.6% had taken pyrantel or albedazole. The incidence of birth defects was 2.36% {64/2711) in the mebendazole group compared with 2.3% (21/913) in the controls (odds ratio 1.03, 95% confidence limits 0.61 - 1.75). This difference was not statistically significant even when corrected for other known risk factors by stratified analysis . Data regarding timing of mebendazole threapy was available for 2660 women; 6.9% in the first trimester, 83.8% in the second, and 9.2% in the third. The incidence of birth defects among women who had taken mebendazole in the first trimester was 3.24% (6/185). giving an odds ratio of 1.42 against the controls; this was also not statistically significant.CONCLUSIONS : The use of mebendazole in pregnancy does not lead to a significant increase in the risk of congenital defects.