Introduction: Studies have evaluated the relationship between obesity and placental pathology report that placentas from obese mothers present villous immaturity, increased inflammatory response (chorioamnionitis, villitis, intervillitis, deciduitis), and vascular and villous lesions of maternal origin. Objective: Analyze the histopathology of placentas from pregnant women categorized by body mass index (BMI). Materials and Methods: 60 placentas capturad in a health entity leve III from Cali:  20 normal weight pregnant women will be evaluated; 20 pregestational obese and 20 gestational obese, between 18 - 37 years old, without associated comorbidities. After signing the informed consent. The placentas will be fixed in 4% paraformaldehyde. Subsequently, four samples will be taken from chorion to decidua, one from each quadrant of the placenta (2 cm3). The histological sections will be stained with hematoxylin-eosin, PAS, PAS diastase and Masson's trichome. Expected results: Identify and quantify placental histopathological features associated with BMI in pregnant women, such as placental inflammatory changes, degree of maturation, chorangiosis, heart attacks, thrombosis, fibrin deposits and calcifications. Conclusions: Studying the histopathological characteristics of placentas from obese pregnant women could provide relevant information for making clinical decisions in the follow-up of the newborn and the reduction of future impacts caused by the effects of an adverse utero-placental environment caused by obesity. This could also show a public health problem related to the increase in maternal obesity. Conflict of Interest: There are no conflicts of interest.