Abstract Background Women may become pregnant while using contraceptives. Commonly used contraceptives containing spermicides may or may not be associated with an increased occurrence of structural birth defects. Study Design Utilizing data from the National Birth Defects Prevention Study, we assessed maternal reports of spermicide and male condom use 1 to 3 months following conception among case ( n=11,050) and control ( n=4723) mothers. We assessed the association between spermicide use and 27 types of birth defects and that between condom use and 32 types of birth defects. Results Maternal spermicide use during the first 3 months following conception was associated with a significant increase in the occurrence of only 1 of 27 birth defects, perimembranous ventricular septal defects (adjusted odds ratio=2.40, 95% confidence interval=1.25–4.62). There was no significant association between maternal use of male condoms during the first 3 months following conception and any of 32 types of birth defects. Conclusions The increased occurrence of perimembranous ventricular septal defects among spermicide users may be real or may be a chance finding. Overall, the findings are consistent with those of most previous studies that observed no increased risk for birth defects among spermicide users.