Study Population
Between July 2007 and February 2011, pregnant women receiving health service and prenatal care through the Mexican Social Security System (Instituto Mexicano del Seguro Social –IMSS) were recruited into the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) study. The inclusion criteria were: <20 weeks gestation, at least 18 years old, planned to stay in Mexico City for the next 3 years, had telephone access, reported no medical history of heart or kidney disease, no daily alcohol consumption, and no use of any steroid or anti-epilepsy medications. Following birth, 681 mother-child dyads are actively followed, 605 completed the 48 month visit and 569 completed the 72 month visits and has the necessary covariates for analyses. The institutional review boards at the Harvard School of Public Health, Icahn School of Medicine at Mount Sinai, and the Mexican National Institute of Public Health approved the procedures of the study. Women provided written informed consent.