Buprenorphine vs. Methadone in Treating OUD in Pregnant People

pregnant woman with hand on belly

We regularly write and publish articles about the impact of the drug overdose epidemic and the opioid crisis in the United States. We cover everything from how the overdose and opioid crisis began, how it’s changed over the past two and a half decades, to the measures local, state, and federal officials have taken to mitigate the harm caused by this devastating public health emergency.

We focus on subjects related to treatment and support, such as harm reduction, medication-assisted treatment, and reducing barriers to care for people with opioid use disorder (OUD), because that’s our role: we offer people with OUD the best possible care available, so they can rebuild their lives and live free from the painful cycles of opioid addiction, a.k.a. opioid use disorder (OUD).

Here’s a short list of articles on the opioid crisis you can find in the blog section of our website:

The Opioid Crisis: Treating Opioid Use Disorder (OUD) in West Virginia

Opioid Crisis Report: Potential Fentanyl Vaccine Makes Headlines

Telehealth More Important Than You Realize: Lessons From COVID Apply to the Opioid Crisis

We encourage you to read those articles if you don’t know much about the opioid crisis: they’ll give you a good idea of how it started, how it developed, and where we are now.

This article is a follow-up to an article we published in October 2022 about a specific population of people with OUD – pregnant people – and the impact different types of public policies have on pregnant people with OUD.

Here’s a link to that article:

Prenatal Substance Use Policies: What Helps Mothers With Opioid Use Disorder (OUD)?

The authors of that study identified two things that have a significant positive impact on outcomes for pregnant people with OUD: social services and treatment with medication for opioid use disorder (MOUD) in medication-assisted treatment (MAT) programs.

This article will examine a new study on the two Food and Drug Administration (FDA) approved medications for OUD – buprenorphine and methadone – in order to learn which medication improves outcomes most for pregnant people with OUD.

OUD and MAT During Pregnancy: Facts, Figures, and Risks

We’ll preface this with something everyone reading this article should understand:

In all studies that compare outcomes for pregnant people OUD, people in MAT programs show improved outcomes for both the pregnant person and the fetus.

With that said, let’s take a look at what we know about the relationship between the opioid crisis and pregnancy. A study published in January 2021 showed rates of neonatal abstinence syndrome and opioid use disorder (NAS and OUD) among pregnant women between 2010 and 2017. Note: neonatal abstinence syndrome occurs when a baby is born to a mother with OUD, and the baby shows signs of opioid withdrawal, as a result of in utero exposure to opioids.

Here’s the data from the 2021 study:

  • Prevalence of NAS:
    • 2010: 4.0 per 1,000
    • 2017: 7.3 per 1,000
  • Prevalence of maternal OUD:
    • 2010: 3.5 per 1,000
    • 2017: 8.2 per 1,000

Those figures indicate that between 2010 and 2017, prevalence of neonatal abstinence syndrome (NAS) increased by 82 percent, and OUD among pregnant mothers increased by 131 percent. Additional research shows the risks of OUD during pregnancy:

  • Premature labor
  • Fetal convulsions
  • Premature birth
  • Unhealthy birth weight (low weight)
  • Elevated rate of birth defects
  • Neonatal abstinence syndrome (NAS)

However – as we mention above – there’s a way to help pregnant women with OUD: medication-assisted treatment (MAT). Evidence shows that pregnant women with OUD who participate in an MAT program with FDA-approved MOUD decrease the risk of all the potential negative consequences listed above.

With that in mind, let’s take a look at that new study that compares outcomes for pregnant mothers with OUD in MAT programs with buprenorphine and pregnant mothers with OUD in MAT programs with methadone. Since both decrease risk of adverse outcomes, this study can help us learn which medication decreases risk more effectively.

MAT During Pregnancy: Which Leads to Better Outcomes – Buprenorphine or Methadone?

Published in June 2022 in the Journal of Substance Use and Misuse, the meta-analysis “Buprenorphine Compared with Methadone in Pregnancy: A Systematic Review and Meta-Analysis” reviewed data from 7,251 patients in 20 studies conducted in Europe, North America, and Oceania (Australia, New Zealand, Melanesia, Micronesia, and Polynesia).

Among the study participants – all of whom were pregnant, had OUD, and in an MAT program with MOUD – a total of 3,105 took buprenorphine during pregnancy and 4,146 took methadone during pregnancy. Of the studies included in the meta-analysis, 8 studies provided adjusted results for a total of 4 outcomes: birth weight, body length, premature birth, and neonatal abstinence syndrome.

Here’s what they found:

  • Average Birth Weight:
    • Buprenorphine: 6.9 lbs.
    • Methadone: 6.4 lbs.

Average Difference: 0.5 lbs. in favor of buprenorphine

  • Body Length:
    • Buprenorphine: 19.4 inches
    • Methadone: 18.8 inches

Average Difference: 0.6 in. in favor of buprenorphine

  • Percentage and Risk of Prematurity:
    • Buprenorphine: 14% of pregnancies resulted in premature birth
    • Methadone: 21% of pregnancies resulted in premature birth

Fetuses exposed to buprenorphine were born prematurely at a lower rate than fetuses exposed to methadone. Those exposed to buprenorphine were born prematurely at a rate 7% lower than fetuses exposed to methadone. Fetuses exposed to buprenorphine had a 40% reduced risk of premature birth, compared to fetuses exposed to methadone.

  • Percentage and Risk of Neonatal Abstinence Syndrome (NAS):
    • Buprenorphine: 33% received treatment for NAS symptoms
    • Methadone: 61% received treatment for NAS symptoms

Fetuses exposed to buprenorphine received treatment for NAS at a lower rate than fetuses exposed to methadone. Those exposed to buprenorphine had a 40% reduced risk of receiving treatment for NAS, compared to fetuses exposed to methadone.

MAT During Pregnancy: Results Show Buprenorphine Superior to Methadone

This meta-analysis – which examined data from 20 studies – reports that fetuses exposed to buprenorphine in utero, compared to fetuses exposed to methadone in utero, show the following:

  • Heavier average weight at birth
  • Longer average length at birth
  • Lower risk of premature birth
  • Decreased risk of neonatal abstinence syndrome (NAS)

That’s important information for treatment providers like us. It’s also important for local, state, and federal policymakers, who make decisions regarding the allocation of funding for programs designed to mitigate the harm caused by the opioid crisis.

This study shows that for pregnant people with OUD who choose to participate in an MAT program with and FDA-approved MOUD, buprenorphine reduces several risks associated OUD during pregnancy more effectively than methadone.

The study authors indicate that more research is needed on this topic, especially with regards to long-term outcomes for the mother and long-term developmental outcomes for the children. Here’s how the authors conclude their study:

“This meta-analysis shows that buprenorphine is associated with improvements in growth when compared to methadone. The priority for opioid replacement care programs remains the delivery of nonjudgmental support, addressing of individual needs and maintenance of stability of treatment.”

We can agree with the first point because we see these outcomes ourselves, and we can agree with that second point – the priority for opioid replacement programs – because that’s what we do every day: deliver nonjudgmental support for any individuals – including those who are pregnant – who need the best care available for opioid use disorder (OUD).