THE EFFECT OF POSTOPERATIVE EPIDURAL ANALGESIA AFTER CESAREAN SECTION ON THE PLASMA CONCENTRATION OF PROLACTIN AND INFANT WEIGHT GAIN

Objective: The purpose of this study was to determine the effect of postoperative epidural analgesia after cesarean section on the plasma concentration of prolactin and infant weight gain. Method: Sixty healthy parturients at term undergoing elective cesarean section under epidural anesthesia were equelly and randomly allocated to receive or not receive postoperative management epidural bupivacaine (n=30 in analgesia group or control group). Epidural analgesia was performed for 72 hrs with a continuous epidural infusion (2ml/h) of 0.2% bupivacaine. The plasma concentration of prolactin was measured with radioimmunoassay (RIA). Result: (1) VAS pain scores after operation were significantly lower in the analgesia group than in the control group (P0.01). (2) In both groups prolactin levels were significantly higher after operations (P0.01). The increase was greater, however, in the analgesia group (P0.05). (3)There were negative correlations between VAS scores (24h and 48h postoperation) and the plasma concentration of prolactin. (4) Lactation started earlier in analgesia group than in control group (P0.05). (5) The infant weight gain was more marked in the analgesia group (P0.05). (6) The duration by which the intestine resumed its motor function was greatly shortened in analgesia group (P0.01). And patients in analgesia group had better sleep. There were no severe complications except that 3 cases complained numbness of pelvic limbs. No difference was observed in uterus contraction (P0.05). Conclusion: Continuous epidural bupivacaine after cesarean section produced a satisfactory postoperative pain relief, an increased secretion of prolactin, improvement of breast feeding and a marked gain of infant weight.