【Objective】 To study whether combined spinal-epidural analgesia (CSEA) and patient-control epidural analgesia (PCEA) has influence on maternal and umbilical cord blood gas. 【Methods】 Fifty healthy nulliparas who accepted CSEA+PCEA were selected as the study group

meanwhile another 34 nulliparas without CSEA+PCEA were selected as the control group

they all had vaginal delivery. The delivery process and the effect on mother and fetus were compared between the two groups. The blood gas analysis of the newborn umbilical arterial blood was observed (pH

PO2

and PCO2 ). 【Result】 Though the duration of latent phase

active phase and the second stage of labor in the analgesia group were longer than the control group

the complications of mother and fetus were not increased. The pH

PO2

and PCO2 of umbilical arterial blood in the analgesia group and the control group were (7.27±0.06) vs (7.29±0.06)

(58.40±9.12) mmHg vs (55.11±8.64) mmHg

(17.07±6.41) mmHg vs (16.89±5.08) mmHg. There were no significant differences in two groups (P<0.05). 【Conclusions】 CSEA +PCEA have no impact on umbilical cord blood gas and pregnancy outcome.