Effectiveness of cervical cerclage in preventing recurrent preterm
birth: a retrospective study
Abstract
Objective: This study aimed to clarify the effectiveness of cervical
cerclage in preventing recurrent preterm births. Design: A retrospective
study. Setting: The perinatal registration database of the Japan Society
of Obstetrics and Gynecology Perinatal Center from 2014 to 2016.
Population or Sample: For this study, 6,060 multiparous women with a
history of preterm birth were reviewed. After excluding 17 subjects who
had unknown indications for cervical cerclage, 6,043 subjects were
included in this study. Methods and main outcome measures: The
efficacies of elective, ultrasound-indicated, and emergency cerclage as
preventive treatments for women with a history of preterm birth were
evaluated by comparing the cerclage and non-cerclage cases. Prior to
evaluation, a propensity score matching was performed for elective and
ultrasound-indicated cerclage patients. Results: Elective cerclage did
not reduce the risk of preterm birth in subsequent pregnancies for any
of the pregnancy periods (p = 0.413). Similarly, ultrasound-indicated
cerclage was ineffective (p = 1.000). In addition, for
ultrasound-indicated cerclage, Kaplan-Meier survival curves showed that
the risk of a subsequent preterm birth might increase at < 33
weeks of gestation. However, the hazard ratio could not be determined to
be statistically significant using the log-rank test at < 28
weeks of gestation. In contrast, emergency cerclage significantly
reduced the risk of subsequent preterm birth for all pregnancy periods
(p < 0.001). Conclusions: Subsequent preterm births were
effectively prevented only in emergency cerclage cases. For elective and
ultrasound-indicated cerclage, statistically significant differences in
subsequent preterm births were not evident.