Background:

The aim of this study was to evaluate changes in leisure-time physical activity (LTPA) and its correlates from prepregnancy to the postpartum period in mothers enrolled in a Brazilian birth cohort study. Our hypothesis was that LTPA would decline considerably during pregnancy.

Methods:

Maternal LTPA in the 3 months before pregnancy and during each trimester of pregnancy was assessed soon after delivery. A follow-up visit was conducted 3 months later. Weekly frequency and duration of each session of LTPA in a typical week were assessed for each period and a cut-off point of 150 minutes per week was used to classify women as active or not.

Results:

The proportion of women active in leisure time declined from 11.3% in the prepregnancy to 2.3% in pregnancy and 0.1% in the postpartum period (P for trend <0.001). When considering any LTPA practice, the decline ranged from 15.4% to 4.4% and 7.5% (p for trend <0.001), respectively. Higher income, higher education and lower parity were the main predictors of LTPA practice.

Conclusions:

LTPA declined considerably during pregnancy and did not return to prepregnancy levels at 3 months postpartum. Mothers must be advised on the benefits of LTPA prepregnancy, during, and postpregnancy.