MAVRIC: a multicenter randomized controlled trial of transabdominal vs transvaginal cervical cerclage

Abstract

Background: Vaginal cerclage (a suture around the cervix) commonly is placed in women with recurrent pregnancy loss. These women may experience late miscarriage or extreme preterm delivery, despite being treated with cerclage. Transabdominal cerclage has been advocated after failed cerclage, although its efficacy is unproved by randomized controlled trial.

Objective: The objective of this study was to compare transabdominal cerclage or high vaginal cerclage with low vaginal cerclage in women with a history of failed cerclage. Our primary outcome was delivery at <32 completed weeks of pregnancy.

Study design: This was a multicenter randomized controlled trial. Women were assigned randomly (1:1:1) to receive transabdominal cerclage, high vaginal cerclage, or low vaginal cerclage either before conception or at <14 weeks of gestation.

Results: The data for 111 of 139 women who were recruited and who conceived were analyzed: 39 had transabdominal cerclage; 39 had high vaginal cerclage, and 33 had low vaginal cerclage. Rates of preterm birth at <32 weeks of gestation were significantly lower in women who received transabdominal cerclage compared with low vaginal cerclage (8% [3/39] vs 33% [11/33]; relative risk, 0.23; 95% confidence interval, 0.07-0.76; P=.0157). The number needed to treat to prevent 1 preterm birth was 3.9 (95% confidence interval, 2.32-12.1). There was no difference in preterm birth rates between high and low vaginal cerclage (38% [15/39] vs 33% [11/33]; relative risk, 1.15; 95% confidence interval, 0.62-2.16; P=.81). No neonatal deaths occurred. In an exploratory analysis, women with transabdominal cerclage had fewer fetal losses compared with low vaginal cerclage (3% [1/39] vs 21% [7/33]; relative risk, 0.12; 95% confidence interval, 0.016-0.93; P=.02). The number needed to treat to prevent 1 fetal loss was 5.3 (95% confidence interval, 2.9-26).

Conclusion: Transabdominal cerclage is the treatment of choice for women with failed vaginal cerclage. It is superior to low vaginal cerclage in the reduction of risk of early preterm birth and fetal loss in women with previous failed vaginal cerclage. High vaginal cerclage does not confer this benefit. The numbers needed to treat are sufficiently low to justify transabdominal surgery and cesarean delivery required in this select cohort.

Keywords: failed cerclage; late miscarriage; transabdominal cerclage; vaginal cerclage.