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 Yale School of Medicine in New Haven, Conn., 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; however, just over 2 percent of women in both studies took them for longer periods.
“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.
“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.” Particularly 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 the incidence of babies born addicted is 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 up-to-date 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, 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.
In the two recent studies, opioids were used most often by pregnant women to treat back pain or abdominal pain. But in an editorial published in Anesthesiology, Dr. Flood and a co-author, Dr. Srinivasa 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 are ameliorated by alternatives like physical therapy. 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. Non-steroidal anti-inflammatory drugs are rarely used, but 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.