Use of prescription narcotic painkillers during pregnancy is common, which significantly increases chances of babies to be born premature or with low birth-time survival rate, showed a new study. Also, there is a high possibility of the baby to experience drug withdrawals.

At least 30% of expectant mothers in Tennessee were found using opioids, like hydrocodone, oxycodone, morphine, or codeine. Lead study author Dr. Stephen Patrick said that study results were surprising as many women were using prescribed opioid pain relievers during pregnancy.

"I was also surprised by how commonly women smoked in pregnancy, and how much that increased the risk of neonatal abstinence syndrome among those who also used opioid pain relievers in pregnancy", said the Vanderbilt University neonatologist and assistant professor of pediatrics.

Patrick said that it makes sense for some women to take opioids in pregnancy as it helps improve their infant's outcome. Use of maintenance opioids like methadone is known to reduce chances of preterm birth compared to heroin for women with opioid dependency. Risk of neonatal abstinence syndrome is higher in infants of these women, but it is much better than the alternative, which is preterm birth.

Patrick went on to say that dose didn't alter the risk of neonatal abstinence syndrome for women in maintenance treatment. However, smoking played a big role, which means it is possible to significantly decrease the infant's risk of drug withdrawal by curbing smoking habit.

Patrick raised concerns over increasing rates of prescription painkillers in the United States, calling for the need of monitoring for any kind of trend like this.

For the study, researchers analyzed the medical records of more than 112,000 women on the Tennessee Medicaid program between 2009 and 2011. Findings of the study were published online April 13 in the journal Pediatrics.