Pregnancy is a unique time resulting in rapid physiological changes during which nearly half of women experience an upward postpartum shift in body mass index (BMI) category. With an increasing number of women of reproductive age undergoing bariatric surgery, we sought to determine if pregnancy following Roux-en-Y gastric bypass (RYGB) or laparoscopic adjustable gastric banding (LAGB) diminished postoperative weight loss.
We evaluated 727 women ages 18 to 45 participating in the multi-site, Longitudinal Assessment of Bariatric Surgery (LABS-2) study who underwent RYGB (n = 556) or LAGB (n = 171). Only first and singleton pregnancies in the study period were analyzed. Participants’ measurements were obtained at baseline and yearly follow-up visits through 5-years. Multivariable linear regression was used to evaluate the association of pregnancy on postoperative percent weight change adjusting for baseline age, BMI, education, smoking status, and bariatric procedure type.
In our cohort, preoperative age was 36.1 ± 6.3 years (mean ± SD), baseline BMI was 46.9 ± 7.0 kg/m2, 81.4% identified as white, 74.2% had post-high school education, and 44.7% reported household income less than $50,000. Nearly 12% (n = 65) of women who underwent RYGB and 9% (n = 15) who underwent LAGB had at least one pregnancy during the 5-year follow-up period. Mean time in months between bariatric procedure and subsequent pregnancy was 30.8 ± 14.1 and 25.9 ± 14.5 for RYGB and LAGB, respectively. After adjusting for covariates, women who became pregnant relative to those who did not, were not significantly different in mean postoperative percent weight change between baseline and 5 years (β = 2.07%, 95% confidence interval: -0.95 to 5.10; P = 0.18).
Among women of reproductive ages in the LABS-2 study, pregnancy following bariatric surgery did not significantly affect weight loss compared to women who did not become pregnant during the 5-year study period.