Gestational weight gain and postpartum weight retention after bariatric surgery: data from a prospective cohort study

Abstract

Background: It is unknown whether international guidelines on gestational weight gain can be used in pregnancies after bariatric surgery.

Objectives: To investigate gestational weight gain, intrauterine growth, and postpartum weight retention in postbariatric women.

Setting: 8 Belgian hospitals.

Methods: Prospective data from 127 postbariatric pregnancies from September 2014 through October 2018. Patients were grouped according to achievement of 2009 Institute of Medicine (IOM) guidelines.

Results: In 127 patients with a mean age of 30.2 years (standard deviation [SD], 4.7), the mean gestational weight gain was 12.5 kg (SD, 6.7). Of these patients, 24% (30 of 127) showed insufficient weight gain, 20% (26 of 127) showed adequate weight gain, and 56% (71 of 127) showed excessive weight gain. Of 127 patients, 27 (21%) had small-for-gestational-age infants. This peaked in the group with insufficient weight gain (47%; 95% confidence interval [CI], 29%-65%; P < .001). The prevalence of large-for-gestational-age infants was comparable between groups, although highest in the group with excessive weight gain (0% in those with insufficient weight gain, 4% in those with adequate weight gain, and 8% in those with excessive weight gain). Preterm births were recorded more in patients with insufficient weight gain (23%; 95% CI, 8%-38%; P = .048). The mean amounts of postpartum weight retained were 4.0 kg (SD, 7.4) at 6 weeks and 3.0 kg (SD, 9.1) at 6 months. Weight retention at 6 weeks (7.1 kg; 95% CI, 5.5-8.7; P < .001) and 6 months (8.3 kg; 95% CI, 4.5-12.2; P < .001) was highest in women gaining excessive weight.

Conclusion: Achievement of IOM guidelines is low in postbariatric pregnancies. Insufficient weight gain increases the risk for small-for-gestational-age babies. Excessive weight gain increases weight retention after delivery and could precipitate weight regain. After bariatric surgery, women should be encouraged to achieve IOM recommendations.

Keywords: BPD; Billiopancreatic diversion; Gastric banding; Gastric bypass; IUGR; Sleeve gastrectomy.