The effect of anesthetic method for prophylactic cervical cerclage on plasma oxytocin: a randomized trial

This study compared the changes in plasma oxytocin, intraoperative hemodynamics and postoperative uterine activity in patients who underwent elective Shirodkar cerclage for cervical incompetence with general or spinal anesthesia.

Thirty-seven singleton pregnant patients were enrolled in this prospective, randomized, controlled comparison of general (n=17) and spinal anesthesia (n=20) for elective Shirodkar suture in the second trimester. Plasma oxytocin concentration was measured before, 1 h after, and 24 h after the procedure. Uterine activity was recorded by external tocography twice daily for 30 min over a three-day period.

Plasma oxytocin concentration did not change significantly after cerclage in either group. There were no significant differences between the two groups at any time. None of the patients reported painful contractions during study period. Two (11.8%) and four patients (20.0%) in the general and spinal groups, respectively (NS), showed increased uterine activity but these symptoms disappeared without treatment. The systolic blood pressure in the spinal group was significantly lower after anesthesia compared with the baseline and was significantly lower than in the general group during the procedure.

Anesthetic method used for elective Shirodkar procedure did not affect the perioperative changes in plasma oxytocin nor postoperative uterine activity.