Pregnancy Within 1 Year of Weight-Loss Surgery Carries Added Risks

MONDAY, May 10, 2021 (HealthDay News) -- Women who get pregnant within a year of having weight-loss surgery are more likely to have preterm and smaller-than-normal babies, a new study suggests.

Dutch researchers said their findings support current recommendations to avoid pregnancy for 12 to 24 months after weight-loss (bariatric) surgery.

"We should encourage women who wish to conceive after bariatric surgery to avoid pregnancy until their weight has stabilized, to minimize the risk of inadequate gestational weight gain," the researchers said.

The aim is to head off problems due to ongoing weight loss and an increased risk of malnutrition due to significantly lower calorie intake.

The study of 196 women compared three groups -- those who conceived within 12 months of weight-loss surgery (early group); those who got pregnant between 12 and 24 months (middle group); and those who conceived more than 24 months (late group) after surgery.

Compared to the other two groups, the 23.5% of women in the early group had shorter pregnancies (267.1 days versus 272.7 and 273.1 days, respectively). Those in the early group lost an average 1.9 pounds during pregnancy, while the women in the other groups gained between 22 and 23 pounds. Newborns in the early group also weighed less — 6.56 pounds versus 6.97 and 7.08, respectively.

"Although the difference … in neonatal birth weight is probably not clinically relevant, the lower gestational age in the 'early' group might be alarming as we also found a trend towards more preterm births in this group," researchers noted in a news release.

Laura Heusschen of Vitalys Obesity Clinic at Rijnstate Hospital in Arnhem, Netherlands led the study.

Her team also linked inadequate weight gain with earlier delivery and lower birth weight.

Women whose weight gain was deemed inadequate delivered at 266.5 days on average versus 273.8 those whose weight gain was adequate, researchers found. Their babies weighed one-third of a pound less.

Inadequate pregnancy weight gain was also associated with a higher rate of preterm births (15.9% vs. 6%) compared to pregnancies with adequate weight gain.

The findings are to be presented at the European Congress on Obesity virtual annual meeting, being held Monday through Thursday. Research presented at meetings is typically considered preliminary until published in a peer-reviewed journal.

"In order to break the vicious cycle of obesity and its health consequences, it is important that future research and clinical care focus on the prevention of babies being born small for gestational age after bariatric surgery," they said in a meeting news release.

More information

The Society for Maternal-Fetal Medicine has more on pregnancy after weight-loss surgery.

SOURCE: European Congress on Obesity, news release, May 8, 2021