Changes in retained weight and waist circumference during the first six months postpartum : a latent growth curve model

Few studies have measured the changes of postpartum weight retention (PWR), and none of them have assessed the effect of pregnancy on waist circumference (WC) in Taiwanese women. The primary aims of this longitudinal study were to explore the changes in body weight and WC during the first six months postpartum and to identify the explanatory factors of PWR and of WC. A theoretical framework that incorporated Bandura's social learning theory and the results of a literature review was used to guide this study. Structured questionnaires were used for data collection. Postpartum body weight and WC were measured. Data were collected from May 2011 to January 2013 and analyzed using the SPSS 19.0 and Mplus 6.12. A sample of 200 healthy postpartum women was recruited from three clinics in Tainan City, Taiwan. The mean age of the women was 31.19 years, and the majority of them were married (98.0%), primiparas (56%), had a bachelor's degree (52.5%), and planned to have this pregnancy (62.5%). The mean prepregnancy body weight was 55.84 kg, and the mean GWG was 13.76 kg. About one third of the sample gained weight exceeding the GWG recommendations of the IOM. The mean PWR decreased over time from 9.13 kg at hospitalization to 2.73 kg at 6 months postpartum. Approximately 24% of the participants still retained 5 kg or more at 6 months postpartum, and about 44% of the women had at least one kind of weight-related risk--substantial PWR, overweight, or central obesity. Age, prepregnancy BMI, parity, GWG, and place for doing the month significantly affected PWR. The final latent growth curve (LGC) model of PWR explained 91.5% and 33.9% of the variance in initial status and overall change rate in PWR. Age, prepregnancy BMI, parity, GWG, and cesarean delivery significantly affected WC, which explained 84.1% and 38.1% of the variance in initial status and change rate in WC. GWG was the most influential factor in the change rate of PWR and WC. Establishing tailored recommendations for GWG for Taiwanese women is warranted.