The Division of Population Health Research (DiPHR) at the Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD) designs and conducts original epidemiological, behavioral, and biostatistical research encompassing several research domains such as human reproduction and development, pregnancy and related complications, pediatric and adolescent health and behaviors, and methodologic research relevant for our mission. Under the developmental origins of health and disease (DOHaD) hypothesis, early life exposures can “program” an individual for health and chronic disease risk through cellular adaptations to biological processes. Prenatal exposures impact fetal growth and development and neonatal health, important determinants of life-long health and disease. The purpose of the SPAN research study is to learn more about how different factors in pregnancy lead to healthy babies. We propose an approach to examine timing of delivery in relation to fetal and neonatal health and development. This contract is to support in the ongoing collective recruitment and follow-up of approximately 3,450 women with uncontrolled gestational diabetes for randomization to timing of delivery. For women who decline randomization, enroll, and consent up to 3,000 women for chart abstraction only. For this Stage 2, the contractor is required to recruit approximately 65 subjects and make every effort to recruit as many subjects as possible to ensure the most successful outcomes during this phase.