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.