Gestation is a period of physiological and metabolic changes that seek to ensure the normal maternal-fetal growth. However, you can submit during this period, a variety of problems for both mother and fetus [1]. Anemia is one of the most prevalent and of greater impact during pregnancy. Also of note is the importance of nutritional status of pregnant women and their relationship with adverse pregnancy outcomes. Limited existing knowledge about the relationship of nutritional status of pregnant women with anemia in pregnancy. In terms of Latin America are limited studies about existing and, for methodological and sample characteristics, make it difficult to extrapolate our population. Objective: To determine the relationship between nutritional status according to body mass index and factors in the presence of anemia in pregnant women based on data from the ENSIN 2005. Methods: we conducted an observational study of analytical prevalence, based on data collected by the ENSIN 2005 Profamilia survey in the period from October 25, 2004 and July 15, 2005. Results: A significant association was able to establish some factors such as the trimester of pregnancy in anemia as hemoglobin (higher risk in the 2nd quarter OR: 0.53, 95% CI 0.32 to 0.86, p = 0,0104) and socio-demographic factors of type (region of residence and marital status). Conclusions: We emphasize the importance of investigating more deeply about the social determinants and their relationship to the development of anemia and believe it is necessary to design policies aimed at improving the nutritional status of the population, deserve primary attention for pregnant women.
