# Two-stitch versus one-stitch cervical cerclage in women with high risk for preterm birth: a stratified exploratory randomized controlled trial in China

## TL;DR

This study compared two surgical techniques for preventing early birth in high-risk pregnancies in China, finding no major difference in most cases but a hint that one method might help prevent very early births.

## Contribution

The study is the first stratified RCT comparing two-stitch and one-stitch cerclage techniques in both therapeutic and emergency settings for preterm birth prevention.

## Key findings

- In therapeutic cerclage, two-stitch did not reduce preterm birth before 34 weeks compared to one-stitch.
- Emergency cerclage with two-stitch was linked to fewer births before 28 weeks, though not for the primary outcome.
- Neonatal survival rates were similar between groups in both cohorts.

## Abstract

Cervical insufficiency or sonographic short cervix is a major cause of preterm birth (PTB). The efficacy of two-stitch versus one-stitch cerclage remains controversial, with limited evidence from randomized controlled trial (RCT), especially stratified by indication.

We conducted a single-centre, stratified, exploratory RCT at Fujian Maternal and Child Health Hospital, Fuzhou, China. Women with singleton pregnancies were enrolled into two parallel cohorts: a therapeutic cohort (ultrasound-indicated; cervical length ≤ 25 mm at 16–28 weeks) and an emergency cohort (physical examination-indicated; painless cervical dilatation with or without membrane exposure at 16–28 weeks). Within each cohort, participants were randomly assigned (1:1) to receive McDonald cerclage with either two-stitch or one-stitch. The primary outcome was spontaneous PTB < 34 weeks. RR with 95% CI was calculated as the primary measure of effect size between groups.

Between June 2022 and December 2024, 100 women were enrolled and stratified (therapeutic, n = 50; emergency, n = 50). In the intention-to-treat (ITT) analysis, there was no significant difference in the primary outcome of spontaneous PTB < 34 weeks between the two-stitch and one-stitch groups in the therapeutic cohort (16.0% vs 0.0%; RR not calculable; p = 0.110) or the emergency cohort (40.0% vs 48.0%; RR 0.83, 95% CI 0.44–1.57; p = 0.569). However, an exploratory analysis of the emergency cohort revealed that the two-stitch technique was associated with a reduced incidence of PTB < 28 weeks (12.0% vs 40.0%; RR 0.30, 95% CI 0.09–0.96; p = 0.024). Neonatal survival rates did not differ significantly in either cohort.

In the therapeutic setting, the two-stitch technique was not superior to the one-stitch approach. For emergency cerclage, while the primary outcome was not significantly reduced, a secondary analysis showed an association between the two-stitch technique and a reduced incidence of extreme PTB < 28 weeks. This hypothesis-generating finding suggests a potential benefit in preventing extreme PTB < 28 weeks and must be validated in larger, definitive trials.

The Chinese Clinical Trial Registry (ChiCTR), Identification Number ChiCTR2200058540. https://www.chictr.org.cn/bin/project/edit?pid=159942.

The online version contains supplementary material available at 10.1186/s12884-026-08809-8.