The efficacy of therapeutic cervical cerclage in singleton pregnancies: a retrospective study

Abstract

Objectives

We compared the pregnancy prolongation effect attributable to cervical cerclage to that achieved by conservative management, and determined the cervical length for which cervical cerclage is effective.

Methods

We retrospectively examined medical records of 281 women admitted to our hospital between January 2013 and December 2017 for management of threatened preterm birth at 22−28 weeks of gestation. Obstetricians determined suitability for cervical cerclage, which was performed using the McDonald procedure in all cases. Of the 281 subjects, 71 underwent cervical cerclage (cerclage group); the other 210 received conservative therapy (non-cerclage group). We recorded maternal and neonatal characteristics of all patients. The two groups were compared in terms of length of extension of pregnancy and weeks of gestation at delivery. Multivariate analysis was performed to identify factors associated with extension of time to delivery.

Results

Our analyses revealed that the cerclage group was hospitalized earlier in pregnancy than the non-cerclage group (23.7 ± 1.5 weeks vs. 26.4 ± 1.9 weeks, p < .001) and had shorter cervixes (6.0 ± 9.4 mm vs. 16.9 ± 13.0 mm, p < .001). The two groups did not differ significantly in terms of gestational weeks at delivery. Multivariate analysis regarding extension of pregnancy revealed significant differences in extension of pregnancy related with cervical cerclage (26.65 days, 95% CI 17.0 − 36.3, p < .001) and cervical length <10 mm (−27.4 days, 95% CI −36.0–−18.8, p < .001). While the time to delivery was extended by cervical cerclage in women with short cervixes (<25 mm), the two groups did not differ when cervical length was ≥15 mm.

Conclusions

Cervical cerclage was a significant positive factor and short cervix was a significant negative factor for elongating pregnancy. In primigravida and multigravida women with no history of preterm birth, when the cervix is short (<10 mm), cervical cerclage should be recommended.

Keywords:

• Cervical cerclage
• cutoff
• period of extended pregnancy
• preterm birth
• short cervix

Acknowledgments

The authors thank Editage (https://www.editage.com/) for English-language editing. The authors thank Atsushi Kubo to support data collection from the medical record.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Additional information

Funding

This research was funded by Japanese Red Cross, Nagoya 1st. Hospital Research Grant. The funding body played no role in study design, data collection, analysis or interpretation and writing of the manuscript.