VALENCIA, Spain—Fetal growth is decreased after maternal bariatric surgery, according to results from the so-called AURORA study, which were presented by Roland Devlieger, MD, PhD, from UZ Leuven in Belgium at the 20th World Congress in Fetal Medicine.

Risk factors associated with fetal growth restriction/small for gestational age were higher gestational weight gain, lower body mass index before conception, and not receiving nutritional advice before pregnancy. 

“Maternal bariatric surgery mimics in-utero starvation,” Dr. Devlieger said. 

He explained that the potential determinants of fetal growth after bariatric surgery were placental function, maternal nutrition, glycemic control, gut microbiome, and pollutants. 

He also introduced the GLORIA study, a multicenter, prospective, controlled cohort study in 95 women, aged 18 to 45 years, who have had bariatric surgery and are up to 12 weeks pregnant, and 95 matched-controls in whom blood glucose levels will be continuously monitored during 10 consecutive days and 4 times during the pregnancy. The growth and body composition of the babies will be monitored by ultrasound, during routine obstetrics consultations. The study is still recruiting participants.

Roland Devlieger, MD, PhD (Photo by Larry Luxner)

Finally, Dr. Devlieger highlighted a paper published by his team, which contains consensus recommendations for periconception, antenatal, and postnatal care in women who have had bariatric surgery.

According to this, pregnancy should be postponed until weight has stabilized following bariatric surgery. Oral contraception should be avoided as should caffeine and alcohol. Small and frequent meals should be consumed and prepregnancy multivitamin and mineral supplementation should be given.

During the pregnancy, fetal growth should be monitored every trimester, as should gestational weight gain. 

Following birth, breastfeeding is recommended but maternal micronutrients should be monitored during lactation.

Bariatric surgery, which consists of gastric banding, gastric sleeve, or gastric bypass, can be used for the management of morbid obesity. Up to 50% of bariatric surgeries are performed in women of reproductive age.


Devlieger R. Fetal growth after maternal bariatric surgery. Oral presentation at: 20th World Congress in Fetal Medicine; June 28, 2023; Valencia, Spain.