Malabsorptive bariatric surgery linked to fetal growth restriction

Reuters Health Information: Malabsorptive bariatric surgery linked to fetal growth restriction

Malabsorptive bariatric surgery linked to fetal growth restriction

Last Updated: 2015-12-01

By Shannon Aymes

NEW YORK (Reuters Health) - Maternal malabsorptive bariatric surgery was associated with fetal growth restriction in a study from France.

Dr. Laurent Mandelbrot of the University of Paris-Diderot noted in an email to Reuters Health, "Many women suffering from obesity have bariatric surgery before becoming pregnant. This can be beneficial for their health and for their pregnancy. However, some studies raised concern that some of these procedures may increase the risk of fetal growth restriction."

"Fetal growth restriction was increased in women having certain types of bariatric surgery that cause malabsorption, principally gastric bypass. This may be due to metabolic deficiencies related to malabsorption of vitamins and nutrients," Dr. Mandelbrot continued.

Dr. Mandelbrot and colleagues conducted a single-center, retrospective case control study of deliveries in women with a history of bariatric surgery compared with a control group matched for body mass index (BMI) who had not had bariatric surgery and delivered during the same period. To further understand the role restrictive versus malabsorptive bariatric surgery played in fetal growth, outcomes of the subgroups were compared to the control group.

The study included 139 patients with 81 having restrictive surgery and 58 having malabsorptive bariatric surgery, according to an article online November 25 in the American Journal of Obstetrics and Gynecology.

The study group had a mean pre-surgery BMI of 45, pre-pregnancy BMI of 34.1, and an absolute mean weight loss of 31 kg. They were found to have less gestational diabetes but higher gestational weight gain than the control group.

Compared to the control group, the study group had significantly lower birth weights (3317 g/7.3 lb versus 3528 g/7.8 lb, p=0.001).

There were no differences in pregnancy outcomes related to complications, gestational diabetes, hypertension, rate of preterm delivery, rate of cesarean section, or pregnancy weight gain between the groups.

However, the mean birth weight was lower in the gastric bypass or malabsorptive (3093 g/6.8 lb) group than the restrictive (3473 g/7.6 lb) and matched control group (3493 g/7.7 lb, p<0.001).

"This difference was accounted for by a decreased incidence of LGA (large for gestational age) and an incidence of SGA (small gestational age) three times higher in the bypass group than in the restrictive group and controls," the researchers wrote.

Finally, after adjusting for SGA risk factors they found that gastric bypass continued to be associated with SGA (adjusted odds ratio 7.16).

Dr. Mandelbrot further noted, "There is a need to study whether more recent procedures, especially sleeve gastrectomies, also increase the risk of fetal growth restriction. It is important that all young women undergoing bariatric surgery are followed carefully including with fetal ultrasound and receive appropriate nutritional supplements."

Dr. Nicolas Galazis of Whittington Hospital in London, UK, told Reuters Health by email, "Evidence in the literature demonstrated that the incidence of small-for-gestational-age or fetal growth restriction increases in women who have undergone bariatric surgery compared to women with no history of bariatric surgery. This is a potentially important issue and complication following bariatric surgery."

"A less developed fetus in utero is more vulnerable to various insults and is at higher risk of developing intrapartum fetal distress and asphyxia, postnatal hypoglycemia, impaired brain development, and possibly type 2 diabetes and hypertension in adult life. Given these potential adverse outcomes of fetal growth restriction, it is very important to clarify and quantify this risk in women undergoing bariatric surgery in order to be able to provide accurate information to our patients," he said.

"In addition, the authors aim to see if there is a benefit, that is, a decrease in the incidence of small for gestational age/fetal growth restriction after different types of bariatric surgery. They conclude that women who underwent a restrictive procedure like gastric band have less incidence of small for gestational age babies compared to those who had a malabsorptive procedure," Dr. Galazis said.

The authors reported no funding or conflicts of interest.


Am J Obstet Gynecol 2015.

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