What substance is associated with milder neonatal abstinence syndrome (NAS) when used during pregnancy?

Buprenorphine is associated with milder neonatal abstinence syndrome (NAS) when used during pregnancy compared to other substances. This is due to its partial agonist properties, which allow for a more stable pharmacologic profile. Buprenorphine can reduce the severity of withdrawal symptoms in neonates because it binds to opioid receptors in the brain but results in a lower level of activation than full agonists like methadone or oxycodone.

When a pregnant individual uses buprenorphine, the fetus is exposed to a lower overall opioid load, which can lead to less severe withdrawal symptoms after birth. It's also known that the withdrawal symptoms from buprenorphine tend to start later and are less intense than those from full agonist opioids, which contributes to a smoother transition for the newborn.

In contrast, the other substances have a higher potential for producing more severe NAS. Methadone is a full opioid agonist and is often associated with more pronounced withdrawal symptoms in neonates. Oxycodone, being a full agonist as well, can lead to significant NAS due to its potency and the rapid onset of withdrawal effects in infants. Suboxone, although it contains buprenorphine, also has naloxone, which