Certain genes may protect infants born to addicted mothers

Genes tied to addiction in adults may help guide doctors to better treatments for infants born withdrawing from narcotics, according to researchers who identified the genetic link.

Babies exposed in the womb to opioid drugs who have certain variations to two genes had less severe withdrawal symptoms than those without the variants, according to a study in the Journal of the American Medical Association. The babies left the hospital sooner and needed fewer treatments, researchers said.

Drug withdrawal in newborns, called neonatal abstinence syndrome, affects about 22,400 babies each year who are exposed in utero to opioid drugs like methadone and heroin, the authors said. The study, the first to look at the link between genetics and opioid withdrawal in infants, may help researchers find more effective way to treat these babies, said Jonathan Davis, senior study author and chief of newborn medicine at Floating Hospital for Children at Tufts Medical Center in Boston.

“Our goal is to identify the highest-risk babies early, try to develop treatment strategies that will prevent some of the withdrawal and try to get the babies home sooner,” Davis said. “These babies are so uncomfortable and in the hospital for such a long time, we’re talking millions and millions of dollars of health care costs for something that we have to try to prevent.”

Researchers looked at 86 mother-child pairs from July 2011 to July 2012. The babies were exposed to addiction treatments methadone or buprenorphine while in the womb. They all had their DNA analyzed.

The researchers found that infants with a variation of the OPRM1 gene were in the hospital 8.5 days fewer than those who didn’t have the variation. They also had a higher chance of not needing any treatment. Those with a variation of the COMT gene stayed about 10.8 fewer days in the hospital and had less treatment. Both genes in their common form without variations are associated with a higher risk of opioid addiction in adults, the authors said.

Mothers who smoked or who took certain psychiatric drugs also had babies who were at greater risk for withdrawal symptoms, although there weren’t enough women in the study to make the findings statistically significant, the authors said. The results also suggested that breast-feeding may reduce withdrawal symptoms, Davis said.

More studies are needed to duplicate these findings, Davis said. The U.S. National Institutes of Health is starting a larger study now, he said.

“What we’re hoping we’ll be able to do is take a few drops of saliva from the mother or a few drops of blood and tell her the possible risk and severity of her baby withdrawing from prenatal exposure to narcotics,” Davis said.