Nine months postpartum weight retention predictors for Brazilian women

To identify factors potentially associated with weight retention measured 9 months after childbirth. Prospective study with four follow-up waves in time (0.5, 2, 6 and 9 months postpartum). Rio de Janeiro, Brazil. 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. 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 or =12 kg, body fat at baseline > or =30% and infant birth weight