MATERNAL AND FETAL CONCENTRATION OF MORPHINE AFTER INTRATHECAL ADMINISTRATION DURING LABOR

Healthy women (25) in labor received morphine 1-1.75 mg in normal saline intrathecally. The residual pain was evaluated on a scale for 0-5 at 10 (score 2.5) and 25 min (score 1.5). After delivery the maternal and fetal plasma morphine concentrations were measured by radioimmunoassay in 14 parturients. Of the 25 women, 23 had vaginal deliveries, 20 of them without forceps. The maternal and fetal plasma concentrations of morphine were .gtoreq. 6 ng/ml. The intrathecal (but not extradural) administration of morphine is effective and could provide an alternative for pain relief in labor.