Combined influence of preconception body mass index and gestational weight gain on fetal growth

Abstract

Background: The Chilean Ministry of Health has been using standards for nutritional evaluation and weight gain recommendations during pregnancy in the last 25 years. In the meantime new standards have been developed. Aim: To study the combined influence of preconception maternal nutritional status and gestational weight gain, using new standards to classify those parameters, on perinatal outcomes. Material and Methods: A cohort of 11,465 healthy pregnant women was prospectively followed until term. Their pre-gestational nutritional status was classified using the body mass index cut-offs in use in the United States (USA). Their gestational weight gain was classified using categories proposed in a Danish study. Perinatal outcomes included were risky birth weight, i.e. < 3000 g and >= 4000 g, and cesarean delivery Relative risks for those perinatal outcomes were calculated for all combined categories of pre-gestational nutritional status and gestational weight gain. Results: Relative risks of almost all gestational weight gain results were statistically significant for women having a normal pre-gestational nutritional status meanwhile all of them were not significant for underweight women. Overweight and obese women had similar relative risks values as normal women. However, many of them were not significant, especially in obese women. Conclusions: There is an independent and combined influence of preconception nutritional status and gestational weight gain on perinatal outcomes, when using standards to classify those parameters developed in the USA and Denmark, respectively (Rev Med Chile 2011; 139: 710-716).