The Division of Intramural 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. The Division comprises three intramural research branches Epidemiology, Biostatistics & Bioinformatics, and Health Behavior, and its mission is to design and implement original research with the potential for high impact findings for public health and its special populations. Accumulating evidence from animal and human studies suggests that adverse intrauterine exposures may lead to permanent fetal adaptions in anatomy and physiology, which may be beneficial for short term fetal survival, but result in an altered long-term risk of disease later in life. Maternal obesity and gestational diabetes mellitus (GDM) are exposures of particular interest given that a very high proportion of women (~25%) are obese when becoming pregnant. Moreover, hyperglycemia in pregnancy as exemplified in GDM has long been regarded as a teratogen which affects fetal structure, function, and development and has long-term adverse impacts on the offspring. Data from mechanistic studies indicates that fetal exposure to obesity and/or hyperglycemia may lead to long-term metabolic and vascular function alteration. Thus, investigators at the NICHD have designed and will implement a cohort study of offspring of an existing cohort of mothers using both retrospective and prospective data collection to evaluate impacts of GDM and obesity on the metabolic, vascular, and reproductive health of the offspring, their determinants and the underlying molecular mechanisms