Modifiable Determinants of Postpartum Weight Loss in Women with Obesity: A Secondary Analysis of the UPBEAT Trial.

Pregnancy can alter a woman's weight gain trajectory across the life course and contribute to the development of obesity through retention of weight gained during pregnancy. This study aimed to identify modifiable determinants associated with postpartum weight retention (PPWR; calculated by the difference in pre-pregnancy and 6 month postpartum weight) in 667 women with obesity from the UPBEAT study. We examined the relationship between PPWR and reported glycaemic load, energy intake, and smoking status in pregnancy, excessive gestational weight gain (GWG), mode of delivery, self-reported postpartum physical activity (low, moderate, and high), and mode of infant feeding (breast, formula, and mixed). At the 6 month visit, 48% (n = 320) of women were at or above pre-pregnancy weight. Overall, PPWR was negative (-0.06 kg (-42.0, 40.4)). Breastfeeding for ≥4 months, moderate or high levels of physical activity, and GWG ≤9 kg were associated with negative PPWR. These three determinants were combined to provide a modifiable factor score (range 0-3); for each added variable, a further reduction in PPWR of 3.0 kg (95% confidence interval 3.76, 2.25) occurred compared to women with no modifiable factors. This study identified three additive determinants of PPWR loss. These provide modifiable targets during pregnancy and the postnatal period to enable women with obesity to return to their pre-pregnancy weight.

Lifestyle Interventions in Overweight and Obese Pregnant or Postpartum Women for Postpartum Weight Management: A Systematic Review of the Literature.

Excessive gestational weight gain (GWG) and postpartum weight retention (PPWR) may predispose women to the development of obesity. The objective of this systematic review was to evaluate the effectiveness of lifestyle interventions in overweight or obese pregnant and/or postpartum women for managing postpartum weight up to 2 years after giving birth. Eighteen randomised controlled trials were included (2559 participants) and divided into three categories according to the timing of the intervention: pregnancy only (n = 3), postpartum only (n = 12) and pregnancy and postpartum (n = 3). The intervention duration varied from 10 weeks to 10 months and included diet only (n = 5) or diet and physical activity (n = 13). Seven postpartum only interventions reported significant improvements in postpartum weight when compared to the control group. Most of these interventions were short and intensive, lasting 10⁻16 weeks. One pregnancy only and one pregnancy and postpartum intervention reported reduced PPWR at 6 months. Nine trials did not report an effect of the intervention on postpartum weight. However, of these, four reported associations between GWG and PPWR. This review suggests that successful postpartum weight management is achievable with intensive lifestyle interventions starting in the postpartum period; however, there is insufficient evidence to conclude whether interventions starting in pregnancy are effective. Larger trials utilising comparative methodologies in the pregnancy and postpartum periods are required to inform the development of targeted strategies preventing PPWR or reducing postpartum weight.