Is opioid use safe for women trying to conceive? Study links it to miscarriage and lower chance of pregnancy
Opioid use among women trying to conceive may be associated with a lower chance of pregnancy, suggest researchers from the National Institutes of Health (NIH). Moreover, opioid use in early pregnancy may be associated with a greater chance of pregnancy loss. The analysis reveals that opioid use before conception was associated with a 29% lower chance of achieving pregnancy during a given monthly cycle, compared to women who had not used opioids. Among the women who became pregnant, those who used opioids around the time of conception were 1.5 times as likely to have a miscarriage as women who had not. Women who used opioids in the first four weeks of pregnancy were more than twice as likely to have a miscarriage. Women who used opioids in weeks four through eight of pregnancy were 2.5 times as likely to have a miscarriage.
“Our findings indicate that women who are pregnant or planning a pregnancy should, along with their physicians, consider the potential effects opioids may have on their ability to conceive or sustain a pregnancy,” writes Dr Kerry Flannagan, the primary author of the study, which has been published in Epidemiology. Dr Flannagan is a postdoctoral researcher in the Division of Intramural Population Health Research at NIH's Eunice Kennedy Shriver National Institute of Child Health and Human Development.
Opioids are a class of drugs used to reduce pain. According to the research team, opioids are commonly prescribed to women of reproductive age, including after delivery and miscarriage. They argue that while much of the research on prescription opioid use has focused on the effects of drug dependency, little information exists on non-habitual, periodic opioid use around the time of conception and early in pregnancy. “We examined the association of opioid use during the critical window of pregnancy establishment with fecundability (the probability of a woman or female animal conceiving within a given period) and pregnancy loss,” the authors explain.
The researchers analyzed data from the Effects of Aspirin in Gestation and Reproduction (EAGeR) trial, which investigated low-dose aspirin as a treatment to prevent pregnancy loss. Participants were women, in the age group of 18 to 40 years, with a history of one or two pregnancy losses. Women were followed for six-monthly cycles if they did not get pregnant and throughout pregnancy if they did. The women provided urine samples, which were analyzed for various prescription opioids.
Of the 1,228 women in the study, 226 (18%) had used opioids while trying to conceive and 33 (5%) of 685 women who became pregnant had used opioids in early pregnancy. None tested positive for methadone or buprenorphine, typically used to treat opioid dependence. “Opioid use while attempting pregnancy was associated with reduced fecundability. Risk of pregnancy loss increased as opioid exposure was detected later in gestation, from the beginning of the cycle of conception (relative risk: 1.5) to week 4 of pregnancy (relative risk: 2.1), and week 4 and 8 of pregnancy (relative risk: 2.5),” says the team. They add, “Our results are consistent with the hypothesis that opioid exposure while trying to conceive may be harmful, even among healthy, non-opioid-dependent women.”
The authors have called for additional research on how opioid use affects fertility and early pregnancy. The team suggests that until more is known, patients and physicians should evaluate the potential risks and benefits of opioids for pain management among women who are pregnant or may become pregnant, including those undergoing assisted reproduction procedures that may involve opioid treatment to manage pain.