There is no randomized controlled trial evidence that giving naloxone to all babies who have been exposed to maternal opioids (for analgesia in labour) improves any clinically meaningful outcomes (such as need for neonatal intensive or special care, time to establish feeding, neonatal seizures) over placebo or no treatment; all the outcomes assessed in the trials were proxy outcomes.

Some of the nine trials, enrolling 316 newborn infants in total, did report improvements in measures of respiratory function (expired carbon dioxide and alveolar ventilation); however, these outcomes are of little clinical relevance.

There remains the serious theoretical risk of harm to infants at risk of neonatal abstinence syndrome secondary to long‐term in utero exposure to opioids (either illicit or for chronic pain). Naloxone given to such infants may cause acute withdrawal and seizures.