A baby is born every hour in the United States with signs of opiate drug withdrawal, most often because the mother abuses prescription drugs, according to a recent US study.

The study, published in the Journal of the American Medical Association on Monday, also found that the number of new mothers who tested positive for use of opiates, which include powerful painkillers such as oxycontin, increased five-fold between 2000 and 2009.

It is usually not difficult to spot a baby in opiate withdrawal, according to Stephen Patrick of the University of Michigan.

"[They] are far more inconsolable than other babies. They appear uncomfortable, sometimes they breathe a little faster ... they're scratching their faces," he said.

It is unclear if there are long-term health impacts for children born to opiate-addicted mothers who get through their first weeks of life without problems. Some studies on the question have found those kids grow up with a higher risk of developmental problems.

What is clear is that babies born in opiate withdrawal significantly drive up health care costs.

According to the study, the average hospital stay for a newborn in withdrawal averages 16 days, compared to just three days for other newborns. Care costs were more than five times higher.

Source: Agencies