Denmark: Pregnant women with a history of Roux-en-Y gastric bypass (RYGB) surgery are more exposed to hyper- and hypoglycemia than their peers without an RYGB history, claims a study published in Diabetes Care.
Roux-en-Y gastric bypass surgery is the most frequently performed bariatric procedure worldwide and significantly affects weight loss and diabetes remission.
RYGB and pregnancy noticeably alter glucose metabolism, but there is not much evidence of glucose metabolism in pregnancy after RYGB. Thus, Louise L. Stentebjerg from Odense University Hospital in Odense, Denmark, and colleagues set out to investigate interstitial glucose (IG) profiles during pregnancy, the association between the growth of fetus and hypoglycemia in pregnant patients previously underwent RYGB surgery versus control participants, and risk factors linked with hypoglycemia.

For this purpose, the researchers prospectively studied twenty-three pregnant women with RYGB and 23 BMI- and parity-matched pregnant women taken as a control group. Continuous glucose monitoring was done in their first, second, and third trimesters and four weeks postpartum. TIR (time in range) was defined as time with an interstitial glucose level of 3.5–7.8 mmol/L.
The study led to the following findings:
Women with RYGB were four years older than control participants.
Pregnancies occurred 30 months after RYGB, which reduced BMI from 45 kg/m2 presurgery to 32 kg/m2 prepregnancy.
Women with RYGB spent decreased TIR (87.3–89.5% vs. 93.3–96.1%) owing to an approximately twofold increased time above range and increased time below range (TBR) throughout pregnancy and postpartum compared with control participants.
Women with increased TBR had a longer surgery-to-conception interval, lower nadir weight, and more significant weight loss after RYGB.
Women giving birth to small-for-gestational-age neonates experienced slightly increased TBR.
To conclude, blood sugar control is altered in patients with a recent history of bariatric surgery, with a higher risk for a time below range.
"Women with RYGB were more exposed to hypo- and hyperglycemia during pregnancy than control participants," the authors wrote. "Further studies should investigate whether hypoglycemia during pregnancy in women with RYGB is linked with decreased fetal growth."
Reference:
Stentebjerg LL, Madsen LR, Støving RK, Andersen LLT, Vinter CA, Juhl CB, Jensen DM. Roux-en-Y Gastric Bypass Increases Glycemic Excursions During Pregnancy and Postpartum: A Prospective Cohort Study. Diabetes Care. 2022 Dec 7:dc221357. doi: 10.2337/dc22-1357. Epub ahead of print. PMID: 36477853.