Maternal and fetal concentrations of morphine after epidural administration during labor.

In this study of 20 healthy women in labor we attempted to determine the efficacy of epidural morphine as an obstetric analgesic. Four patients experienced some relief of pain while 16 patients reported no effect on pain. One newborn infant demonstrated possible morphine-induced respiratory depression. It was concluded that morphine is ineffective as an obstetric analgesic.