Marceau, K., Hajal, N., Leve, L. D., Reiss, D., Shaw, D., Ganiban, J. M., Mayes, L. C., & Neiderhiser, J. M. (2013). Measurement and associations of pregnancy risk factors with genetic influences, postnatal environmental influences, and toddler behavior. International Journal of Behavior Development, 37, 366–375. PMC: 4018759

Measuring pregnancy complications is important for developmental studies seeking to clarify genetic and postnatal environmental influences on children’s behavioral development. This study presents a comprehensive measure of pre- and perinatal risk factors, the Pregnancy Risk Index, and demonstrates the utility of using aggregates of prenatal risk when studying child behavior. The sample is 561 domestic U.S. adoption triads (birth mothers, 18-month-old adopted child, and adoptive parents). Findings show associations between distinct types of aggregate pregnancy risk and measured genetic risk. Toddler behavior varied with different types of pregnancy risk. Genetic influences on toddler behavior may operate through pregnancy risk, whereas postnatal environmental influences are distinct.