Obesity's increasing prevalence has reached epidemic proportions in the USA, with close to one-third of the adult population affected in 2000. Additionally, there is increasing prevalence of obesity in other industrialised areas of the world such as Europe. Of potentially more concern is the potential risks associated with obesity and related metabolic complications in the developing world. The maternal, fetal, peripartum and neonatal complications of obesity in pregnancy have far-reaching implications for both mother and offspring. Of alarming interest is the increasing rate of obesity among adolescents and the cycle of obesity in future generations it portends. The purpose in this review is to briefly review the maternal perinatal morbidities associated with maternal pregravid obesity. Additionally, we will review evidence of both short- and long-term effect of maternal obesity on the in utero environment as it relates to fetal growth, neonatal body composition and adolescent obesity.