Wachman 2019: naltrexone vs buprenorphine in pregnancy, a small pilot

What they tested

This pilot study looked back at records from one center between 2017 and 2019. It compared 6 mothers and babies where the mother took naltrexone (NTX) for opioid use disorder during pregnancy with 13 where the mother took buprenorphine (BUP).

The researchers compared opioid misuse during pregnancy and up to 6 months after delivery, delivery outcomes, gestational age, birth weight, Apgar scores (a quick check of a newborn's health), neonatal intensive care admissions and neonatal abstinence syndrome.

What they found

Mothers and babies in the two groups were similar, except that cigarette smoking was more common in the buprenorphine group (92% vs 33%).

None of the women on naltrexone had documented opioid misuse, against 23% of those on buprenorphine, a difference that was not statistically significant (P = 0.52).

No naltrexone-exposed babies were diagnosed with neonatal abstinence syndrome, against 92% of buprenorphine-exposed babies. 46% of the buprenorphine-exposed babies needed treatment for it, against 0% in the naltrexone group.

Naltrexone-exposed babies had shorter hospital stays, a mean of 3.2 vs 10.9 days.

Limits

• Only 6 women took naltrexone, far too few to detect uncommon problems.
• It was a look back at records from one center, not a randomized trial, so the two groups may have differed in ways the study couldn't measure.
• The groups weren't fully alike: far more mothers smoked in the buprenorphine group.
• It didn't look at the longer-term health of mothers or children, which the authors say larger studies need to examine.

What it means if you're considering naltrexone

Naltrexone in pregnancy has been little studied, and this small pilot found good early outcomes for the babies of women who took it. With only 6 naltrexone pregnancies at one center, it can't establish safety, and the authors call for larger multicenter studies of long-term safety and effectiveness.