Buprenorphine use, compared with methadone use, in pregnancy has been linked with a slightly lower risk of major congenital malformations in a new study of medications for opioid use disorder (OUD).
Elizabeth A. Suarez, PhD, MPH, with the Division of Pharmacoepidemiology and Pharmacoeconomics, Brigham and Women’s Hospital and Harvard Medical School in Boston, and colleagues published the findings in JAMA Internal Medicine.
The lower risk for buprenorphine was small (risk ratio, 0.82; 95% confidence interval [CI], 0.69-0.97), and methadone use should not be ruled out on that basis, the authors wrote. For some women, particularly those on stable treatment before pregnancy or women who do not respond well to buprenorphine, methadone may be the better choice, they explained.
Either Medication Better Than Not Treating
The authors noted that either medication “is strongly recommended over untreated OUD during pregnancy.”
JAMA Internal Medicine Deputy Editor Deborah Grady, MD, MPH, with the Department of Medicine, University of California, San Francisco, emphasized that recommendation in an editor’s note, highlighting that treatment for OUD is critical to prevent infections, overdose, and death in pregnant women as well as neonatal opioid withdrawal syndrome and fetal death.
She stressed that internists and other primary care physicians have a key role in ensuring pregnant women with OUD receive appropriate treatment.
Given the importance of the issue, she wrote, “we have taken the unusual step of publishing two accompanying invited commentaries.”
Two developments may help increase use of buprenorphine, the study authors wrote. One is a recent study showing lower risk of adverse neonatal outcomes when buprenorphine is used during pregnancy compared with methadone. Another is the removal last year of the prescribing waiver for buprenorphine.
Study Included Medicaid Data Over 18 Years
The population-based cohort study used data from publicly insured Medicaid beneficiaries from 2000 to 2018. Pregnancies with enrollment from 90 days before pregnancy through 1 month after delivery and first-trimester use of buprenorphine or methadone were included (n = 13,360). The data were linked with infants’ health data.
The study group included 9,514 pregnancies with first-trimester buprenorphine exposure and 3,846 with methadone exposure. The risk of malformations overall was 50.9 (95% CI, 46.5-55.3) per 1000 pregnancies for buprenorphine and 60.6 (95% CI, 53.0-68.1) per 1000 pregnancies for methadone.
Major malformations were any cardiac malformations, ventricular septal defect, secundum atrial septal defect/nonprematurity-related patent foramen ovale, neural tube defects, oral clefts, and clubfoot.
Two Invited Commentaries Urge Caution in Interpretation
The two invited commentaries Dr. Grady mentioned in her editor’s note point both to the importance of the team’s findings and the need for better understanding of factors that may affect the choice of which OUD medication to use.
A commentary by Max Jordan Nguemeni Tiako, MD, MS, with the Department of Medicine, Brigham and Women’s Hospital, and colleagues, said that while the Suarez et al. data are important to share with patients, “the ultimate treatment decision must be the result of shared decision-making between a knowledgeable clinician and the patient, rather than promoting one medication over another.”
They urge putting the findings in context given the study population, which comprises a relatively stable group of women with OUD, most of whom were taking OUD medications before they got pregnant. The study sample excludes a substantial number of women who are chronically underinsured or uninsured, Dr. Tiako’s team wrote, because those included were enrolled in Medicaid for 3 consecutive months before pregnancy.
“We urge caution when extrapolating these findings to newly pregnant individuals with untreated OUD,” they wrote.