Investigating Beliefs Toward Physical Activity in Pregnancy Among Women With and Without Gestational Diabetes Mellitus.

OBJECTIVES

Physical activity (PA) is beneficial for pregnant women, including those who develop gestational diabetes mellitus (GDM). However, only a few are sufficiently active to reap health benefits. In this prospective cohort study we aimed to: 1) validate the Theory of Planned Behaviour (TPB) model for predicting moderate-to-vigorous PA (MVPA) among pregnant women; 2) examine whether the model varies by GDM status (with or without GDM); and 3) identify beliefs predicting intention toward MVPA and assess whether these beliefs differ by GDM status.

METHODS

Women with and without GDM completed 2 questionnaires: the first assessed TPB constructs; the second, completed 2 to 4 weeks later, assessed MVPA behaviour. Structural equation modelling and multigroup analyses were conducted.

RESULTS

The sample included 191 women without and 149 with GDM. The main results show that perceived behavioural control (PBC) was a significant moderator of the relationship between intention toward MVPA and the behaviour, the relationship being stronger when PBC was moderate to high. Some beliefs that indirectly predicted the intention toward MVPA varied between women with and without GDM. For example, in women with GDM, higher intention was found in those believing that MVPA would unlikely cause discomfort or pain related to pregnancy (β=0.289, p<0.001), that their health professionals would approve MVPA practice (β=0.149, p=0.023), and that even if they lack time (β=0.282, p<0.001) or are tired (β=0.185, p=0.008), they would practice MVPA.

CONCLUSIONS

Our results highlight the importance of pregnant women's confidence in their ability to be active and of targeting specific beliefs when designing interventions promoting prenatal PA.