Impact of lifestyle in weight control during pregnancy and postpartum

The aim of this thesis is to evaluate the impact of maternal life style on gestational weight gain (GWG) and maternal weight development during postpartum. Firstly, an overview of the literature on indicators used to measure weight changes during and after pregnancy was carried out (article I). Secondly, a multivariate logistic regression model was used to assess the association between prenatal smoking cessation and excessive GWG, according to the Institute of Medicine (IOM) recommendations, in 1.249 women who delivered a term infant in 1984/85 in Stockholm, Sweden (article II). Thirdly, a multivariate linear regression model was used to assess the effect of excessive GWG on maternal body mass index (BMI) at 15 years postpartum. The study population was composed of 483 Swedish women who were followed from delivery date of the index child in 1984/85 to 1999/2000 (article III). Finally, a systematic review with meta-analysis was conducted to appraise the effect of diet, exercise or both on postpartum weight loss (article IV). Comparisons among studies and the interpretation of research findings are complicated due to the variety of indicators used to calculate the GWG and postpartum weight retention. The reasons for non-significant associations between GWG and gestational outcomes were probably owing to poor quality of obstetrics records and selection of wrong indicators to compute GWG (article I). Former smokers were 1,8 times more likely to gain excessive weight during pregnancy than nonsmokers, even after accounting for confounding factors, including alcohol consumption, physical activity to mention a few (article II). Postpartum weight retention at 15 years follow-up was higher among women who gained excessive weight during pregnancy (10,0 kg) than who gained weight according to IOM recommendations (6,7 kg). After accounting for confounding factors, women who gained excessive weight during pregnancy had a significant increase of 0.72 kg/m2 in BMI at 15 years follow-up compared to women who gained within recommendations (article III). Women who exercised did not significantly lose more weight than women in the control group (weighted mean difference (WMD) 0,00; 95% CI 8,63 to 8,63). Women who took part in a diet (WMD 1,70; 95% CI 2,08 to 1,32) or diet plus exercise (WMD 2,89; 95% CI 4,83 to 0,95) program lost significantly more weight than women in the control group. The interventions (diet; exercise; diet and exercise) did not adversely affect the maternal and child health (article IV). The findings indicate the relevance of early identification of women at risk of excessive GWG. Health care providers should give women appropriate advice for controlling GWG and motivate them to lose pregnancy-related weight during postpartum. Additionally, health care providers should recommend women to engage in diet combined with physical activity programs in order to lose postpartum weight and consequently prevent obesity associated with childbearing.