Doctors are prescribing opioid painkillers to pregnant women in astonishing numbers, new research shows, even though risks to the developing fetus are largely unknown.Of 1.1 million pregnant women enrolled in Medicaid nationally, nearly 23 percent filled an opioid prescription in 2007, up from 18.5 percent in 2000, according to a study published last week in the journal Obstetrics & Gynecology. That percentage is the largest to date of opioid prescriptions among pregnant women.Medicaid covers the medical expenses for 45 percent of births in the United States.
The lead author, Rishi J. Desai, a research fellow at Brigham and Women’s Hospital, said he had expected to “see some increase in trend, but not this magnitude.”“One in five women using opioids during pregnancy is definitely surprising,” he added.
In February, a study of 500,000 privately insured women found that 14 percent were dispensed opioid painkillers at least once during pregnancy. From 2005 to 2011, the percentage of pregnant women prescribed opioids decreased slightly, but the figure exceeded 12 percent in any given year, according to Dr. Brian T. Bateman, an anesthesiologist at Massachusetts General Hospital, and his colleagues. Their research was published in Anesthesiology.
Dr. Joshua A. Copel, a professor of obstetrics, gynecology and reproductive sciences at the Yale School of Medicine, said he was taken aback by the findings, which come even as conscientious mothers-to-be increasingly view pregnancy as a time to skip caffeine, sushi and even cold cuts.“To hear that there’s such a high use of narcotics in pregnancy when I see so many women who worry about a cup of coffee seems incongruous,” he said.In both studies, the opioids most prescribed during pregnancy were codeine and hydrocodone. Oxycodone was among the top four. Women usually took the drugs for a week or less; still, just over 2 percent of women in both studies took them for longer periods.
Rates of opioid prescriptions were highest in the South, and lowest in the Northeast. The differences were stark: In the study of women enrolled in Medicaid, 41.6 percent of pregnant women in Utah were prescribed opioids, and 35.6 percent in Idaho. Oregon had the lowest, at 9.5 percent, with New York at 9.6 percent.
“The regional variation really concerned me the most,” said Dr. Pamela Flood, a professor of anesthesiology and pain medicine at Stanford University. “It’s hard to imagine that pregnant women in the South have all that much more pain than pregnant women in the Northeast.”
Prescribing rates for opioids vary widely among adults between states and even adjacent counties, suggesting a lack of attention to potential misuse and abuse in areas with high rates.
Pregnant women are taking more prescription drugs now than at any time in the last three decades, not just opioids, and the safety risks are often not well understood. “Fewer than 10 percent of medications approved by the F.D.A. since 1980 have sufficient data to determine fetal risk,” said Cheryl S. Broussard, a health scientist at the National Center on Birth Defects and Developmental Disabilities.
But some doctors and scientists say they are concerned about recent research demonstrating an association between first trimester use of opioids and neural tube defects, which are malformations of the brain, spine or spinal cord. Mothers of children with neural tube defects reported more use of opioids early in their pregnancies — 3.9 percent — than mothers of children without such congenital defects — 1.6 percent. To control for recall bias, researchers also had a group of mothers of children with other malformations, and found 2 percent reported opioid use.
“Opioid use in very early pregnancy is associated with an approximate doubling the risk of neural tube defects,” said Martha M. Werler, the senior author and a professor of epidemiology at the Boston University School of Public Health. “About half of pregnancies are not planned, so that’s a big chunk of women who may not be thinking about possible risks associated with their behavior.”At the end of pregnancy, prolonged use of opioids can also lead to addiction in infants, a problem known as “neonatal abstinence syndrome.” A 2012 study in JAMA suggested that the incidence ofbabies born addicted to opioids was on the rise.
Last month, the Centers for Disease Control and Prevention started a website for its Treating for Two initiative, which offers clinicians and expecting patients guidance on medication use in pregnancy. The site aims to prevent birth defects and to minimize exposures to potentially harmful medications during pregnancy.At this stage, Dr. James N. Martin Jr., the director of maternal-fetal medicine at the University of Mississippi Medical Center, said he was not “terribly concerned” about a possible link between first-trimester use of opioids and neural tube defects.
Still, Dr. Martin said, “we need to avoid using opioid analgesics as the first-line therapy in pregnant patients to the extent possible, because there is potential risk.”The reasons behind the surge in opioid use are unclear. Pregnancy has always entailed discomfort. A growing fetus may place pressure on the mother’s nerves, causing sciatica. Weight gain, posture changes and pelvic floor dysfunction all can result in discomfort and pain for mothers-to-be.
Certainly, pain caused by kidney stones, a malignancy or chronic conditions like sickle cell anemia justifies opioid use in pregnancy, doctors say. Expectant women who have just had surgery might need narcotics, too.
Dr. Edward Michna, a pain specialist at Brigham and Women’s Hospital, speculated that rising obesity rates may also be increasing the frequency of back problems during pregnancy. But he and others wondered if opioids were being prescribed when acetaminophen might have been a better choice.In the two recent studies, opioids were used most often by pregnant women to treat back pain or abdominal pain. But in an editorialpublished in Anesthesiology, Dr. Flood and Dr. Srinivasa N. Raja, a professor in the anesthesiology department at Johns Hopkins University School of Medicine, noted that back pain, abdominal pain and joint pain were not particularly helped by opioids. More often, they were ameliorated by alternatives like physical therapy.
Still, taking an opioid may be viewed as easier “than more time-intensive use of other therapies,” the editorial said.Dr. Michna does not prescribe narcotics for lower back pain in pregnant women. “We don’t want to expose them to drugs that have unknown effects on developing fetuses,” he said. Instead, he said, he suggests acupuncture, physical therapy or biofeedback.Yet pain relief options for pregnant women are limited at best. Nonsteroidal anti-inflammatory drugs are rarely used because there is evidence of potential risk to the fetus in the third trimester.“If the pain is so severe that acetaminophen is not enough, we have no analgesic option besides opioids,” said Dr. George Saade, the director of maternal-fetal medicine at the University of Texas Medical Branch in Galveston.
The Best Pharmaceuticals for Children Act of 2002 has helped stoke research into safer drugs for the pediatric population, he noted. “But we haven’t had anything similar for pregnant women,” he said.In the past 30 years, the use of prescription medicine by pregnant women in their first trimester has increased more than 60 percent, while the use of four or more medications has more than tripled, according to a 2011 study published in The American Journal of Obstetrics and Gynecology.Pregnant or not, Americans are simply pain-averse, experts say. Dr. Cresta W. Jones, an assistant professor of maternal-fetal medicine at the Medical College of Wisconsin, specializes in helping pregnant women with chronic conditions who need to be on narcotics to manage unbearable pain.
But she also has patients who experience garden-variety discomforts of pregnancy, and managing their expectations is difficult.
“It’s taboo to tell a patient, ‘It’s normal for you to be uncomfortable in pregnancy,’ ” said Dr. Jones, whose office has a policy of discouraging the use of narcotics. “We do have a lot of patient pushback. You have to approach it with empathy and understand the societal expectation in the U.S. of the immediate resolution of pain.”