Teenage girls who’ve undergone obesity surgery may not absorb enough of a vitamin needed to have healthy babies, raising the risk of bearing children with spine and brain birth defects, a study suggests.
While more adolescents are having gastric bypass surgery, little is known about long-term consequences of the procedure, said Diana Farmer, who presented the study today at the American Association of Pediatrics meeting in San Francisco. “The possibility of future birth defects may outweigh the benefit of this bariatric procedure” for adolescent girls, said Farmer, chief of pediatric surgery at Benioff Children’s Hospital at the University of California, San Francisco.
Farmer’s report focuses on two converging trends -- rising rates of adolescent obesity and gastric bypass surgery to combat it. Since 2001, the number of gastric bypasses and other bariatric procedures has risen sixfold, with 220,000 of them done in 2009, according to the American Society of Metabolic and Bariatric Surgery in Gainesville, Florida. About 17 percent of children and adolescents ages 2 to 19 are obese, according to the Centers for Disease Control and Prevention in Atlanta.
“I am not saying the procedure should be ruled out or that obesity is not a problem,” Farmer said in a telephone interview Oct. 1. “But no kids are dropping dead at the age of 18 from obesity.”
Gastric bypass surgery involves sidestepping the upper intestine, which limits the amount of food a person can consume. Other bariatric surgery includes gastric banding that restricts the size of the opening from the esophagus to the stomach.
Farmer’s report highlights a consequence of gastric bypass surgery that leads to insufficient absorption of Vitamin B9, or folic acid, which occurs in the upper intestine. Folate, or folic acid, is a key element in the prevention of spina bifida and other neural tube defects. Patients who undergo the procedure are placed on vitamin supplements to counteract the reduction. Limited research shows adherence to the supplements by teens is 14 percent, according to Farmer’s presentation.
“You can’t just write off these birth defects because they are rare,” said Bruce Wolfe, a Portland, Oregon, surgeon and president of the bariatric surgery association. “But there are adverse effects from the obesity as well. So the practical and ethical dilemma is at what point do you deny a tremendously beneficial procedure.”