Project Summary / Abstract The Massachusetts (MA) Center for Birth Defects Research and Prevention (MCBDRP) proposes to continue its strong track record of conducting etiologic research to identify modifiable risk factors for structural birth defects through its participation in the Birth Defects Study to Evaluate Pregnancy exposureS (BD-STEPS). We will enhance our contributions by leveraging our longstanding relationship with local universities to produce future birth defects researchers. The MCBDRP brings to BD-STEPS our expertise and leadership in pharmacoepidemiology and collaborative utilization of unique data resources to be applied to all three key areas of interest named in the Notice of Funding Opportunity. Our research will utilize existing data from the National Birth Defects Prevention Study and BD-STEPS, as well as data collected in the next iteration of BD- STEPS. The MCBDRP investigators are committed and successful mentors and collaborative partners, roles that will continue and expand within BD-STEPS. Over the three and a half year grant period, the MCBDRP will complete at least seven etiologic research projects of public health significance that will aid in counseling women in considering exposures that are less likely to result in a birth defect; these projects include: 1) Assessing anti-obesity medications that have been and will continue to be approved by FDA and assessing bariatric surgical procedures that are increasingly performed which may lead to beneficial weight loss, though it is uncertain how potential nutritional deficiencies may impact subsequent pregnancies; 2) Investigating attention deficit hyperactivity disorder medications, the use of which has increased dramatically; 3) Evaluating nicotinamide adenine dinucleotide pathway inhibitors and the potential preventive effect of supplementation with niacin; 4) Evaluating medication use during pregnancy by severity classifications of congenital anomalies; 5) Gauging the complex relationship among multiple risk factors to further our understanding of birth defects; 6) Examining anti-viral medications, which are key to preventing maternal-fetal transmission but for which little is known about their safety with respect to birth defects; and 7) Leveraging the MA State Public Health Laboratory’s reportable disease database to explore the role of infections before and during pregnancy on the development of birth defects. Through these activities, the MCBDRP will be an essential partner in BD-STEPS to achieve our overall goal of translating research findings into meaningful initiatives in birth defects prevention.