Recent data show that that the number of prescriptions being written for opioids to manage pain has quadrupled over the past decade in the United States. In 2012, it was estimated that 259 million prescriptions were written for opioids, a figure that amounts to one prescription for every American adult currently living in the U.S. Research suggests that opioids are commonly prescribed in pregnancy, however studies evaluating their association with neonatal outcomes are limited.

In the past, studies have described the effect of drug withdrawal on infants born to mothers who used drugs illicitly, such as heroin or among women receiving medication-assisted treatment. Few studies, however, have examined the dispensing of legal opioid prescriptions for pregnant women. “In light of the nation’s current prescription opioid epidemic, it’s important to look at how these drugs are used by pregnant women and its impact on outcomes for mothers and infants,” says Stephen W. Patrick, MD, MPH, MS.


Exploring the Issue

In a study published in Pediatrics, Dr. Patrick and colleagues sought to identify neonatal complications that were associated with antenatal opioid exposure. The authors also examined predictors of neonatal abstinence syndrome (NAS), a drug withdrawal syndrome in infants following birth that—according to previous research—has been linked to about $720 million per year in national healthcare expenditures for treatment. Previously, studies have suggested that opioid use during pregnancy increases risks for NAS.

The study group used prescription and administrative data that was linked to vital statistics for mothers and infants who were enrolled in the Tennessee Medicaid program between 2009 and 2011. The authors then looked at a random sample of NAS cases that were validated by a medical record review. They assessed the association of antenatal exposures with NAS using multivariable logistic regression and controlled for maternal and infant characteristics.


A Common Occurrence

Of the more than 112,000 pregnant women who were analyzed in the study, over 31,000—or 28%—filled one or more prescriptions for opioids. “This illustrates the fact that pregnant women are commonly being prescribed opioids,” says Dr. Patrick. Babies who were exposed to opioids were more likely to be born preterm, have low birth weights, and develop complications like NAS, meconium aspiration syndrome, and respiratory distress. “In addition,” Dr. Patrick says, “about two-thirds of babies who had NAS were born to mothers that legally filled prescriptions for opioids.” Click here to look at the Birth Injury Law and see if you or someone you know could have a case against the hospital or doctors.


Other Key Findings

The study also found that women who were prescribed opioids were more likely than those who were not to have depression or an anxiety disorder and to smoke tobacco. About 21% of infants with NAS were born at a low birth weight, compared with rates of about 12% for infants exposed to opioids and 10% for infants not exposed to opioids.

Several factors were shown to increase risks for NAS by two-fold, according to the data (Table). These include opioid type and duration of exposure as well as daily tobacco use and selective serotonin reuptake inhibitor use. Not all babies exposed to opioids had drug withdrawal after birth, a finding that Dr. Patrick says warrants more research. Studies are needed to determine the reasons and risk factors for withdrawal symptoms among neonates from opioid use during pregnancy.

When compared with women who had no opioid exposure, pregnant women who used opioids were more likely to be Caucasian, have anxiety or depression, suffer from headaches or migraines, and have musculoskeletal diseases. The majority of women who were prescribed opioids during the study were given short-acting medications. However, 2% received maintenance doses of opioids while less than 1% received long-acting opioids.


Assessing the Implications

“Much of the focus regarding the opioid epidemic has been directed toward adults, but our research shows that more attention should be paid to pregnant women who use these powerful drugs as well as infant outcomes,” says Dr. Patrick. The study notes that the financial impact of outcomes associated with opioid use during pregnancy is also substantial. The study notes that every $1 spent on short-acting opioids in pregnancy was associated with $52 in hospital charges for NAS.

Many states throughout the U.S. have initiated programs like prescription drug monitoring databases to combat overprescribing and “doctor shopping” for opioids. Many healthcare providers and pharmacists across the country are now required by law to use these systems. Including more data on opioid use among pregnant mothers in these monitoring systems may improve neonatal outcomes. “We hope our study gains the attention of state and federal policy makers,” Dr. Patrick says. “Our findings highlight the fact that the prescription opioid epidemic is having a tangible impact on mothers and infants.”