Physical activity during pregnancy among women who are overweight or obese.

Abstract

Background: Being overweight or obese during pregnancy and having excessive gestational weight gain increase the risk of many adverse maternal and neonatal health outcomes. Exercise is beneficial during pregnancy. However, physical activity pattern during pregnancy, the effect of exercise on maternal and neonatal health outcomes, and women’s perception of making healthy change remains unclear. Aims: The aims of this thesis were, for women who are overweight or obese during pregnancy, to • Describe physical activity patterns during pregnancy; • Evaluate available evidence about antenatal exercise interventions; • Test the effects of an antenatal exercise intervention in a randomised controlled trial; and • Explore women’s perceptions of making healthy changes during pregnancy. Methods: To evaluate the above aims, the following methodology was employed: • A nested prospective cohort study to evaluate physical activity; • A systematic review and meta analysis using standard Cochrane methodology; •A randomised controlled trial of an antenatal walking intervention and incorporation of the findings into a meta-analyses of previous literature; and • A mixed-methods investigation of women’s perception of making healthy change during pregnancy. Results: • In women who were overweight or obese, physical activity declined significantly between early pregnancy and 36 weeks’ gestation, before increasing after birth. Physical activity at four months post-partum remained lower than that in early pregnancy. Women with higher BMI had a greater decline in physical activity over pregnancy. There was no significant effect of a simple supervised antenatal walking group on gestational weight gain and other clinical maternal and neonatal health outcomes, as confirmed by a meta-analysis of previous trials, despite better physical fitness and activity level represented by higher commuting and leisure activity in late pregnancy. • A large proportion of women do not consider excessive gestational weight gain to be a concern, with limited awareness of neonatal complications. Women’s barriers to making healthy behaviour changes were highly individualised with limited perception of benefits. Furthermore, women were not confident in their ability to make changes. Conclusions: While providing a walking group is associated with some increase in self reported physical activity, further studies should identify effective strategies to facilitate an increase in leisure activity during pregnancy, overcome perceived barriers, and educate women about both the neonatal health consequences of maternal obesity and health benefits associated with exercise.