The project developed a survey and questionnaire for use in population surveys to assess environmental exposures, lifestyle factors, and genetic factors that may increase the risk of birth defects. The study also focused on development of methods of subject contact and tracking. Questionnaire response rates of mothers were compared between those whose children had birth defects or no birth defects. Additionally, validity of the questionnaires was tracked from responses and the mother's medical record. The subject contact procedures and tracking methods developed in this CHEEC funded pilot study proved beneficial for use in the Iowa Birth Defects Registry in etiologic studies of birth defects. The questionnaire developed in this study was utilized in a project titled Epidemiologic Characterization of Genetic and Environmental Risk Factors for Human Clefts, funded by the National Institute of Dental Research.