Naloxone in the parturient and her infant.

Eighteen women in labor received analgesia with moderately large total doses of meperidien. Various doses of naloxone (8, 12, 18, 27, 40, or 60mug/kg of body weight) were given intravenously to the mothers before delivery in an attempt to find the dose that would prevent neonatal narcotic depression. Maternal and neonatal blood gas values, Apgar scores, and postnatal neurobehavioral examinations were used to assess the effects. Infants born of mothers who had received neither meperidine, promethazine, nor naloxone served as controls. After the naloxone injection, the mothers showed an improvement in consciousness and blood gas values. When the study infants, as a group, were compared with control infants, there was very little difference in blood gas values or neurobehavioral examination. Infants in the groups receiving naloxone in doses of 18, 27, and 40mug/kg compared most favorably with the control infants, indicating that naloxone may be effective in preventing neonatal narcotic depression.