- The more traditional worldwide public health concerns including under-nutrition and infectious disease have been replaced by overweight and obesity as a major contributor to ill health. Indeed, overweight and obesity are prevalent and increasing worldwide. Close to a third of women of childbearing age are classified as obese, and an additional quarter of women in this age group are overweight. The rates of adverse perinatal outcomes and co-morbidities are rising as well. Maternalpregravid obesity is a significant risk factor for adverse perinatal outcomes. Obesity is known to be associated with serious obstetric complications for the mother and the fetus. Obesity is a risk factor for macrosomia, as are pre-gestational and gestational diabetes, which are also more common among overweight and obese patients. The surgical treatment of obesity, i.e. bariatric surgery, is a rapidly growing area of surgical practice today. This reflects both the ability of bariatric surgical procedures to provide a solution to an otherwise unsolvable problem and the evolution of safer, less invasive procedures. The worldwide epidemic of adolescent and adult obesity may not only be a result of our lifestyle of inadequate activity and poor diet. It may also be propagated and enhanced at a much earlier stage in life because of an abnormal metabolic milieu in utero during gestation. Because we know that lifestyle treatment of obesity is rarely successful in the long term, we need to give serious consideration the surgical treatment of obesity and to prevention strategies. Future research should focus on the metabolic environment in utero following bariatric surgery as a mean of restriction the viscous cycle of obesity. In addition, the potential of in utero therapy, possibly through lifestyle measures during gestation for the prevention of fetal-neonatal obesity, should be investigated. Copyrigth © Sociedad Iberoamericana de Información Científica (SIIC), 2009.