Nine months postpartum weight retention predictors for Brazilian women.

OBJECTIVE To identify factors potentially associated with weight retention measured 9 months after childbirth. DESIGN Prospective study with four follow-up waves in time (0.5, 2, 6 and 9 months postpartum). SETTING Rio de Janeiro, Brazil. SUBJECTS AND METHODS Two hundred and sixty-six Brazilian women of childbearing age. Analysis was based on hierarchical logistic regression. The dependent variable was weight retention and was defined as the difference between weight at 9 months postpartum and pre-pregnancy weight, with a dichotomised cut-off at 7.5 kg. Covariates included demographic and socio-economic data, obstetric history, anthropometric data, and data on the infant. These data were grouped in blocks and ordered according to their influence on the dependent variable. RESULTS Of the women studied, 19.2% presented weight retention values > or =7.5 kg. According to the logistic regression analysis, the following variables remained associated with weight retention > or =7.5 kg: total family income, difficulty or inability to read a letter, age category > or =30 years, age at first childbirth <23 years, gestational weight gain > or =12 kg, body fat at baseline > or =30% and infant birth weight <3500 g. Infant hospitalisation was only marginally significant. CONCLUSIONS Determinant factors identified by the analysis highlight the need for nutritional intervention policies during pregnancy and in the first months postpartum as a way of minimising obesity and the diseases resulting from it.