Effect of epidural analgesia and sedo-analgesia on plasma oxytocin levels in labouring primiparous women in University of Port Harcourt Teaching Hospital

Abstract

Objective: To determine the effects of sedo-analgesia and epidural analgesia on plasma oxytocin levels in labouring women.
Design: Prospective comparative study
Setting: University of Port Harcourt Teaching Hospital, Nigeria.
Subjects: Eighty Primiparous parturients in labour.
Results: The maternal socio-demographic variables were similar across the two groups, p>0.05. A three-stage sample collection for plasma oxytocin showed that while the Epidural analgesia (EA) group had 46.88±15.70, 58.71±20.71 and 35.48±14.34 respectively, p=0.002, the Sedo-analgesia (SA) group had 20.57±7.24, 57.36±21.17, and 31.38±10.48 respectively, p=0.00001. While both groups had an increase in the oxytocin level 60 minutes after analgesia, a decrease below baseline immediately after delivery of the placenta occurred in the EA group (58.71±20.71 pg/ml, and 57.36±21.17 pg/ml) respectively, p=0.763. A further fall in oxytocin levels were observed at the delivery of the placenta; EA versus SA (35.48±14.34pg/ml versus 31.38±10.48pg/ml) respectively, p=0.129. The values of plasma oxytocin level at 4cm cervical dilatation and 60 minutes after analgesia was 11.83±30.39 in the EA group and 36.79±21.11 (pg/ml) in the SA group, p= 0.0001. The mean difference in plasma oxytocin level between the samples immediately after placenta delivery and 4cm cervical dilatation for EA and SA groups were 11.4±14.6 and 10.81±9.19 (pg/ml) respectively, p=0.00001.
Conclusion: This study showed that although there was no statistically significant difference in the plasma oxytocin levels between the two groups, higher levels were found in the epidural group, but a fall was observed immediately after placenta delivery in each group.