The current obstetric literature suggests the existence of the impact of obesity on maternal and perinatal outcomes as numerous reports demonstrate critical implications for the antepartum, intrapartum and postpartum periods. Despite of these publications, the extent of that impact remains controversial. Given the increasing prevalence of obesity among women of childbearing age and taking into account that maternal weight above the ideal is one of the few risk factors potentially modifiable, and probably related to an unfavorable pregnancy outcome, strategies that include the prevention of gestational obesity provided even in the periconcepcional period have became important public health actions now. In the present study, the authors perform an on the matter, focusing on the interface of the effects of obesity on the gestational and perinatal prognosis.