Effectiveness of body mass index in the nutritional diagnosis of pregnant women.

Our goal was to analyze the concordances and non-concordances of the nutritional classification in pregnant women and to evaluate their effectiveness when different BMI classification methodologies were applied. The study consisted of 314 adult healthy pregnant women in their first trimester, of socioeconomic status IV. In all of them, two nutritional classification criteria were applied: the integral nutritional diagnosis (IND) and different BMI reference values (Institute of Medicine, FAO/OMS, Frisancho, Bray, and Atalah). Kappa, concordance and non-concordance, sensitivity, specificity, positive and negative predictive values were calculated. The highest frequency of concordance between IND and the analyzed classification criteria in comparing four and three nutritional categories was Frisancho's with the following results 89.2%, Kappa = 0.81 in the first case, and 91.4, Kappa = 0.84 in the second case. In deficit, the Bray and Atalah classification criteria were the highest sensitivities. In excess, FAO/OMS, Frisancho, and Bray had a high sensitivity (1-0.99). Frisancho, in addition, had a high specificity with respect to FAO/OMS and Bray. Frisancho's classification criteria are the best choice for diagnosing adult pregnant women's nutritional status during the first trimester within population groups with these characteristics.