Weight Loss Surgery Can Increase Risk of Birth Complications: Study

A recent study suggests that women who recently underwent bariatric surgery may face a higher risk of birth complications, raising further concerns about the potential side effects of weight-loss surgery. 

Researchers from the University of Washington found that infants born to women who recently had bariatric surgery for weight loss faced a higher likelihood of being born premature, being admitted to the neonatal intensive care unit (NICU) and being born smaller than normal. The findings were published this week in the medical journal JAMA Surgery.

The population based retrospective cohort study examined data from January 1980 to May 2013. at hospitals in Washington State. They collected data from birth certificates and maternally linked hospital discharge data.

More than 10,000 mothers and infants were included in the study, including 1,800 mothers who had prior bariatric surgery, gastric bypass surgery or LAP-Band surgery. Those were compared to a random sample of more than 8,400 nonoperative mothers and their infants matched by delivery year, average age of 29.

Infants born to mothers who had bariatric surgery had a 14% increased risk of being premature, compared to the infants born to mothers who did not have the weight loss surgery. Those infants had a prematurity risk of 8.6%.

The findings of the new study are on par with the findings of a study published in September, which indicated women who had weight loss surgery had a higher risk of experiencing preterm delivery.

Among the participants of the new study, the NICU admission risk for bariatric surgery infants was 15%, compared to 11% for the infants of non-bariatric surgery mothers. Bariatric surgery infants also had a 13% increased risk of being born small for their gestational age.

Other studies have shown bariatric surgery to increase pregnancy complications, including shortened pregnancies and having smaller than normal babies. They were also at higher risk for having infant stillbirths and neonatal deaths.

Recent Weight Loss Surgery Riskier

Researchers found that the time between the bariatric surgery and the pregnancy appeared to be a factor. Infants born to mothers who had operation-to-birth intervals of less than 2 years had the highest risks for prematurity and NICU admission.

Expecting mothers who had bariatric surgery within the last two years had a 17.2% increased risk of giving premature birth, compared to an 11.8% increased risk facing mothers who had bariatric surgery more than four years ago.

They also had higher NICU admissions risk, 17.7% compared to 12.1%. Those infants also had a higher risk of being small for their gestational age, 12.7% versus 9.2%.

Study authors said metabolic changes after maternal bariatric surgery may be the factor that affects subsequent fetal development.

“These findings are relevant to women with a history of bariatric surgery and could inform decisions regarding the optimal timing between an operation and conception,” wrote study authors.

Despite the complications linked to pregnancy, many studies have linked bariatric surgery to other complications, including increased risk and return of type 2 diabetes and hypertension conditions.