Journal of Developmental Origins of Health and Disease (2010), 1(2), 123–130. & Cambridge University Press and the International Society for Developmental Origins of Health and Disease 2010 doi:10.1017/S2040174410000139 ORIGINAL ARTICLE Birth weights smaller or larger than the placenta predict BMI and blood pressure at age 7 years D. P. Misra 1 , C. M. Salafia 2,3 *, A. K. Charles 4 and R. K. Miller 5 1 Division of Population Health Sciences, Department of Family Medicine and Public Health Sciences, School of Medicine, Wayne State University, Detroit, MI, USA 2 Placental Analytics, LLC, Larchmont, NY, USA 3 Institute for Basic Research, Staten Island, NY, USA 4 Department of Pathology, Princess Margaret Hospital, Perth WA, Australia 5 Departments of Obstetrics and Gynecology, Environmental Medicine, Pathology and Laboratory Medicine, School of Medicine and Dentistry, University of Rochester, Rochester NY, USA We hypothesized that the altered placental proportions that influence birth weight affect childhood body proportions, and that these effects would be independent of birth weight. We also hypothesized that altered placental proportions might affect the fetal cardiovascular system, and may be reflected in variation in childhood blood pressure. By using linear regression with birth weight as the dependent variable, placental variables were entered as predictors. The predicted birth weights based on placental factors were then obtained. The ratio of the actual birth weight to that predicted by placental parameters (observed/expected ratio, OER) was used as the independent variable in analyses of age 7 year body mass index (BMI) and diastolic blood pressure (DBP) in the 15,902 singleton liveborns delivered between 34 and 43 weeks. The standardized residual birth weight was also used as a variable to examine the effects of birth weight that is not con- sistent with placental parameters. For each unit increase in the OER, BMI at 7 years increased 1 kg/m 2 (P , 0.0001). The OER also had a significant effect on DBP (b 5 4.52, P , 0.001) at 7 years of age but only among African-American children. Results for the standardized residual birth weight variable were consistent with the OER. All results were adjusted for gestational age, sex, socioeconomic status, African-American race and maternal pre-pregnancy BMI. Being larger or smaller than predicted by one’s placenta affects childhood body composition and blood pressure. The placental measurements provide insight into pathophysiological mechanisms of the developmental origins of adult disease. Received 7 November 2009; Revised 2 February 2010; Accepted 19 February 2010 Key words: placenta, blood pressure, BMI, childhood, race Introduction Overweight and obesity both have been increasing over the past 25 years and the prevalence continues to rise each year. From 1991 to 1998, increases were seen for men and women alike but the highest increases in prevalence of obesity were among the youngest and most educated persons. 1 Even more troubling are the increased rates of overweight and at risk for overweight being seen in children. Among US children 6 to 11 years old in 1999 to 2002, 31% were at risk for overweight or were already overweight. 2 The average BMI for 7-year- old boys in the US rose from 15.9 kg/m 2 in 1963 to 17.0 kg/m 2 in 2002. For girls, average body mass index (BMI) increased from 15.8 to 16.6 kg/m 2 during that period. 3 Furthermore, while hypertension is rare among children, a number of longitudinal studies have now showed that blood pressure appears to track from childhood with a consequently higher likelihood of hypertension for adults who blood pressure fell in the higher end of the distribution in childhood. 4 In response to these trends, a wide range of efforts targeting childhood obesity are now underway, focused on improving nutrition and physical activity in young children. However, within the framework of research on fetal origins of chronic disease, there is now considerable evidence that should direct attention upstream to factors at play at the time a child is born. The placenta may give us a window into the intrauterine environment in which the cumulative consequences of many exposures, genetic susceptibilities and their interactions can be inferred from the earliest stages of pregnancy. A small but growing body of epidemiologic evidence links placental growth to hypertension in adulthood 5,6 although some controversy remains 7 and to higher blood pressures in childhood. 8,9 Recently, a few studies have also reported associations between placental growth and body weight or BMI in childhood as well as adulthood. 10,11 By using measures of placental growth to study fetal origins of blood pressure and body weight in childhood may contribute to a fuller under- standing of the intrauterine forces that drive adiposity and vascular function in children and adults. Furthermore, if placental growth is proven to be a reliable predictor of metabolic and vascular function during childhood, these *Address for correspondence: Dr C. M. Salafia, 93, Colonial Ave, Larchmont, New York, USA. (Email carolyn.salafia@gmail.com)