Pregnant women's third trimester exercise behaviors, body mass index, and pregnancy outcomes

Abstract

Pregnancy and postpartum are determinants of sedentary and low active lifestyles. Before effective physical activity interventions are implemented within this population, it is necessary to prospectively examine, during each trimester, their exercise determinants and behaviors within a theoretical framework. The purposes of this study were to: (a) prospectively examine women's third trimester exercise intention and behavior using the theory of planned behavior (TPB), and (b) examine group differences across the TPB constructs, body mass index (BMI), and birth outcomes for women exercising and not exercising during their third trimester. Participants were 62 pregnant women who completed self-report measures during their third trimester and 6-weeks postpartum. We found that: (a) intention predicted exercise behavior; (b) subjective norm predicted exercise intention; and (c) women exercising during their third trimester had significantly lower postpartum BMI and significantly heavier and longer babies than women not exercising during their third trimester. Our findings support the TPB for understanding women's exercise intention and behavior during their third trimester of pregnancy.