Buprenorphine use in pregnancy linked to decreased fetal breathing movements

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Buprenorphine is currently a recommended medication-assisted therapy option for pregnant individuals with opioid-use disorder (OUD). In fact, it is often the preferred medication over alternatives because of a number of advantages, including the ability to treat via outpatient clinic, low possibility of overdose, and fewer instances of other drug interactions.¹

But, according to a poster presented at the American College of Obstetricians and Gynecologists (ACOG) 2024 Annual Clinical & Scientific Meeting in San Francisco, California, held from May 17-19, 2024, the partial opioid-receptor agonist depresses fetal breathing movements as measured during biophysical profile (BPP) assessments in comparison with a control group made up of other high-risk patients.²

Investigators with East Tennessee State University’s Department of Obstetrics and Gynecology and Quillen College of Medicine teamed up to perform a retrospective chart review of BPP assessments and reports to evaluate how buprenorphine affected BPP results. In line with ACOG recommendations, clinicians perform antenatal BPP testing in the third trimester for patients with OUD because of the modest increased risk of stillbirth. For this study, those results were compared with BPP assessments in patients with chronic hypertension (CHTN).

Not only were investigators interested in the impact of buprenorphine on BPP results and differences between the 2 groups, but they were also looking to see whether any association exists between buprenorphine dosage and any subsequent interventions. A number of other factors were also included in the review, such as instances of intrauterine growth restriction (IUGR), tobacco use, fetal gender, maternal body mass index (BMI), maternal age, and number of prenatal visits.

The analysis included data from July 1, 2016, to June 30, 2020, and excluded patients with multiple gestations, patients with coexisting CHTN who were taking buprenorphine, and patients experiencing other high-risk indicators for antenatal testing, such as preexisting diabetes mellitus. The total daily buprenorphine dosages included for review were 2 mg or less, 3-6 mg, 7-13 mg, and 14 mg or more (range, 0.0625 mg-24 mg).

Data from a total of 227 patients taking buprenorphine and 46 patients with CHTN were included in the study arm and control arm, respectively. The fetuses of patients on buprenorphine were more likely to score zero on the fetal breathing movement portion of the BPP (P = 0.011) than the fetuses of patients with CHTN, although there was no significant association between buprenorphine dosage and fetal breathing. Buprenorphine usage also did not affect other components of the BPP, including amniotic fluid index, fetal tone, or fetal gross movement.

Patients in the buprenorphine group, regardless of dosage, were more likely to abuse tobacco (P < 0.001) and have a lower BMI (P < 0.001) compared with patients in the CHTN arm. Investigators were not able to observe any association between buprenorphine dosage and IUGR, fetal gender, patient weight gain, patient age, or intervention. Buprenorphine dosage did matter when it came to number of prenatal visits, with the 0-2 mg group recording the most visits compared with the 7-13 mg and 14 mg or greater groups (P < 0.001).

“Current guidelines minimize the effects of maternal buprenorphine administration on fetal development,” study investigators concluded. “This study adds to prior research; further study on the dose-related long-term and short-term effects of buprenorphine on fetal development is encouraged.”

References

1. American College of Obstetricians and Gynecologists’ Committee on Obstetric Practice and American Society of Addiction Medicine. Opioid use and opioid disorder in pregnancy. Published August 2017. Accessed May 18. 2024. https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2017/08/opioid-use-and-opioid-use-disorder-in-pregnancy
2. Bulger CM, Lewis N, Olsen M. Buprenorphine decreases fetal breathing movements in fetal biophysical profile assessment. Poster presented at: The American College of Obstetricians and Gynecologists 2024 Annual Clinical & Scientific Meeting. San Francisco, CA. May 17-19, 2024.