In various cohorts, nearly 20% of the population is born at a gestational age significantly deviant from 37-41 weeks (half of those are born too early and half are born too late). This has been shown to have significant health consequences in these offspring. In a series of studies we have shown that prematurely born children are insulin resistant and that by mid-adult life insulin resistance persists and is accompanied by marked abdominal visceral adiposity, both key components of the metabolic syndrome. In addition, children born post-term have increased obesity and are insulin resistant with higher blood pressures and elevated serum lipids, which are all of the risk factors for the metabolic syndrome. We believe that the continuum of gestation is influenced both by environmental and genetic factors, and thus we are interested in discovering new genetic factors that are linked to birth timing.