Obesity has currently reached epidemic proportions, both in Chile and in the world. This condition is associated to a variety of maternal complications in all stages of the vital cycle and during pregnancy. Medical treatment has not proved successful thus resulting in an increase in bariatric surgery in recent years, even when it is not first line treatment. This literature review aims to report updated results of surgical treatment for obesity before and during pregnancy with respect to fertility, gestational diabetes, pre-eclampsia and pregnancy-induced hypertension. It also looks into the possible effects of surgery on fetal development, and its relation to premature delivery, fetal macrosomy, low birth weight and neural tube defects, as well as effects on maternal and fetal outcomes, mainly in nutrition. Lastly, we suggest some recommendations that arise from this review on the role of contraception, nutrition and time between surgery and pregnancy.