The number of women who were addicted to opioids when they delivered babies quadrupled across the nation from 1999 to 2014, according to a federal study released Thursday.
Substantial increases were also found in each of the 28 states for which at least three consecutive years of data were available, according to the report from the Centers for Disease Control and Prevention.
In Massachusetts, the rate went up more than sixfold from 1999 to 2013, the most recent year measured.
“These findings illustrate the devastating impact of the opioid epidemic on families across the U.S., including on the very youngest,’’ Dr. Robert R. Redfield, CDC director, said in a statement. “Untreated opioid use disorder during pregnancy can lead to heartbreaking results. Each case represents a mother, a child, and a family in need of continued treatment and support.’’
The study is the first to examine hospital data about opioid-addicted women delivering babies, and the numbers mirror well-known trends in opioid-exposed newborns.
But it’s not clear whether the report reveals a growing problem or growing attention to it. The authors acknowledge the trend could reflect improved screening and diagnosis of the condition.
Additionally, the federal data do not distinguish between women who have received treatment for their opioid use disorder and those who have not.
In Massachusetts, about 80 percent of pregnant women addicted to opioids are already receiving medication for their addiction when they deliver their babies, said Dr. Munish Gupta, a newborn specialist at Beth Israel Deaconess Medical Center.
“This shouldn’t be viewed as more evidence of a crisis,’’ Gupta said of the CDC report. “We don’t know if the trends mean we’re doing a better job of referring and getting moms to treatment. It could very well be that as a public health system we’re doing better.’’
The study delved into two federal databases of hospital stays from the Agency for Healthcare Research and Quality’s Healthcare Cost and Utilization Project. One provided a national overview, showing that the national prevalence rate of opioid use disorder increased from 1.5 per 1,000 hospital births in 1999 to 6.5 in 2014.
The second dataset collects state-specific information, but some states do not make their numbers public every year. Among the 28 states with three consecutive years of data available, the CDC found wide variability, with Vermont having the highest rate of women with opioid addiction delivering babies, and Washington, D.C., having the lowest.
This may reflect, at least in part, the fact that some states do a better job identifying women with opioid use disorder.
In Vermont, the number increased from 0.5 per 1,000 deliveries in 2001 to 48.6 per 1,000 in 2014. Vermont has the highest rate because the state has long worked to find and treat pregnant women for opioid use, said Dr. Marjorie C. Meyer, vice chair of obstetrics, gynecology, and reproductive sciences at the University of Vermont’s Larner College of Medicine. The state began addressing opioid addiction a decade ago and has been providing buprenorphine to opioid-addicted pregnant women since 2006.
“We have developed across the state very specific programs to treat pregnant women,’’ Meyer said. “Women are coming in for care, we are identifying them, and we are treating them.’’ In states that don’t offer care or have punitive policies, women are more likely to hide their addiction and not be counted, Meyer said.
As in Massachusetts, about 80 percent of opioid-addicted women delivering babies in Vermont are in treatment before they go into labor, Meyer said. In Massachusetts, the rate of addiction increased from 2 per 1,000 hospital births in 1999 to 13.1 in 2013.
Massachusetts health officials have made addressing the opioid crisis a major focus, including developing recommendations for addressing drug-exposed newborns.
The number of pregnant women struggling with addiction still seems to be increasing in Massachusetts, but more are getting into treatment, Gupta said.
“In the short term, our goals are not to reduce this population, but to identify and engage this population,’’ he said.
Opioid-addicted pregnant women take buprenorphine or methadone to prevent withdrawal from illicit heroin or fentanyl, which can endanger the pregnancy. But the babies of womenreceiving these medications may suffer withdrawal symptoms after birth, a condition that hospitals have learned to manage, Gupta said.
It is far better to bring women in for treatment, give them medication, treat the babies for their withdrawal, and keep the family intact, he argued,than it is to shame or scare away women suffering from addiction.
Babies born exposed to opioids are usually in good health. If they need treatment for withdrawal, they’ll stay in the hospital for two or three weeks. Little is known about the long-term effects of opioid exposure in the womb.
“Opioid use disorder during pregnancy is a continuing national problem,’’ said Jean Y. Ko of the CDC’s Division of Reproductive Health and one of the study’s authors. “Having these estimates gives us an idea of the number of women who may benefit from treatment,’’ so states can tailor prevention and treatment efforts.
Massachusetts data, collected by the state separately from the CDC report, show 1.9 percent of women who delivered a live birth in 2015 had evidence of opioid use during pregnancy, up from 1.1 percent in 2011.
The number of Massachusetts newborns who experienced withdrawal symptoms after birth was 14.5 per 1,000 live births in 2015, up from 11.2 per 1,000 in 2011.
Dr. Jordana W. Price, a family physician in Boston Medical Center’s Project RESPECT, a program for addicted pregnant women, said the CDC report “will hopefully bring more attention to families and women who need more support than they’re receiving’’ — especially after they go home with their babies.
“We need to not forget that after the baby’s born, this problem does not go away. This is a lifelong problem, and these women need support.’’
Felice J. Freyer can be reached at felice.freyer@globe.com.
