///2019 Abstract Details
2019 Abstract Details2019-07-13T07:45:15-05:00

Randomized Double-blinded Comparison of Prophylactic Norepinephrine and Phenylephrine Infusion During Spinal Anesthesia for Cesarean Delivery in Twin Pregnancies

Abstract Number: T2B-325
Abstract Type: Original Research

Weijia Du MD1 ; Weijia Du MD2; Xin Fang MD3; Zhendong Xu MD.PHD4; Zhiqiang Liu MD.PHD5


Norepinephrine has recently been regarded as an alternative to phenylephrine for treatment of post-spinal hypotension during cesarean delivery(CD)1, but all of these studies were conducted in singleton pregnant women.Twin pregnancies have become considerably more frequent these years as a result of developing assisted reproductive techniques, however, few data have been published on perioperative maternal hemodynamic changes in twin pregnancies2.The objective of this study was to compare prophylactic infusion of phenylephrine and norepinephrine for maintaining maternal blood pressure after spinal anaesthesia in twin pregnancies during elective CD.


This was a double-blinded, randomized, controlled study including 58 healthy twin pregnant women, gestation>36 weeks and scheduled for CD under spinal anesthesia. After spinal induction, either norepinephrine 6μg/ml or phenylephrine 75μg/ml was started infusion at a fixed rate of 1ml/min . Systolic arterial pressure(SAP) was targeted near baseline until delivery.The infusion was stopped if the SAP was more than baseline. Side effects were treated properly.The primary outcome was maternal cardiac output(CO). Other parameters of maternal hemodynamics, cord gases, Apgar score and adverse events were also compared.


Data were analyzed from 56 patients (28 patients in each group, from Dec 2017 to Dec 2018). From infusion until delivery, for norepinephrine versus phenylephrine, there was no difference between groups in CO(7.35L/min vs. 7.31 L/min, P =0.91)(Fig). Maternal hemodynamic parameters including SAP , heart rate, systemic vascular resistance and stroke volume were similar (all P >0.05). The umbilical arterial pO2 of Twin A in norepinephrine group was higher than that in phenylephrine group (P = 0.04). Other neonatal outcomes and incidence of maternal nausea and vomiting, hypotension, bradycardia and reactive hypertension were similar between groups.


When administered as a prophylactic fixed-rate infusion, phenylephrine and norepinephrine are both appropriate selections for maintaining maternal blood pressure after spinal anaesthesia in twin pregnancies. There is no clear evidence that norepinephrine is superior to phenylephrine in this study.


1.Ngan Kee WD, Lee SW, Ng FF, et al. Anesthesiology 2015;122(4):736-45.

2.Lavie A, Ram M, Lev S, et al. Arch Gynecol Obstet 2018;297(2):353-63.

SOAP 2019