We aimed to determine the association between polycystic ovarian syndrome (PCOS) and cervical incompetence (CI). We hypothesise that insulin resistance induces a glucose metabolism disorder that could potentially cause cervical incompetence, resulting in an adverse outcome. We conducted a systematic review and meta-analysis of observational studies to summarise the evidence regarding the strength of the association of occurrence of CI in a PCOS pregnant woman compared to a non-PCOS pregnant woman. We defined PCOS as the presence of two of the three Rotterdam criteria, and a combination of clinical symptoms and ultrasound findings were used to diagnose CI. This review adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020) reporting standards and the PROSPERO registration. We systematically searched PubMed, Embase and Cochrane databases to identify observational studies up to December 2022. We included studies in English which compared the PCOS and non-PCOS pregnant women who were diagnosed using Rotterdam criteria and subsequently developed CI in the same pregnancy. We excluded the studies which did not report CI as an outcome. Two reviewers independently screened studies, extracted data, and assessed the risk of bias (JBI critical appraisal tools). In the meta-analysis, effect estimates were pooled using the random effects model, and heterogeneity was measured using I statistics. We identified 23 articles, of which 19 were screened, and three studies were included in the meta-analysis. Three observational studies reported the data of 3845 pregnant women with PCOS and 9449 pregnant women without PCOS. One hundred and forty-one (3.7 %) pregnant women with PCOS developed CI compared to 58 (0.6 %) non-PCOS pregnant women [Risk ratio: 5.3; 95 % confidence interval: 1.9–14.6; I: 89 %]. Of the three studies included, two had a low risk of bias, and one had a moderate risk of bias. The findings of the review suggested higher risk of CI in a pregnant woman with PCOS compared to pregnant women without PCOS. These findings highlight the necessity of establishing guidelines for early identification of CI in PCOS pregnant mothers to prevent adverse maternal and neonatal outcomes following preterm labour.

中文翻译：

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多囊卵巢综合征与宫颈机能不全之间的关联：系统评价和荟萃分析

我们的目的是确定多囊卵巢综合征（PCOS）和宫颈机能不全（CI）之间的关联。我们假设胰岛素抵抗会诱发葡萄糖代谢紊乱，可能导致宫颈机能不全，从而导致不良后果。我们对观察性研究进行了系统回顾和荟萃分析，总结了与非 PCOS 孕妇相比，PCOS 孕妇与 CI 发生关联强度的证据。我们将 PCOS 定义为存在三个鹿特丹标准中的两个，并结合临床症状和超声检查结果来诊断 CI。本次审查遵循系统审查和荟萃分析的首选报告项目 (PRISMA 2020) 报告标准和 PROSPERO 注册。我们系统地检索了 PubMed、Embase 和 Cochrane 数据库，以识别截至 2022 年 12 月的观察性研究。我们纳入了英文研究，对使用鹿特丹标准诊断并随后在同一妊娠中发生 CI 的 PCOS 和非 PCOS 孕妇进行了比较。我们排除了未报告 CI 作为结果的研究。两名评审员独立筛选研究、提取数据并评估偏倚风险（JBI 关键评估工具）。在荟萃分析中，使用随机效应模型汇总效应估计，并使用 I 统计量测量异质性。我们确定了 23 篇文章，其中 19 篇经过筛选，荟萃分析中纳入了 3 项研究。三项观察性研究报告了 3845 名患有 PCOS 的孕妇和 9449 名没有 PCOS 的孕妇的数据。 141 名 PCOS 孕妇 (3.7%) 发生 CI，而非 PCOS 孕妇则为 58 名 (0.6%) [风险比：5.3； 95% 置信区间：1.9–14.6；我：89%]。在纳入的三项研究中，两项研究具有低偏倚风险，一项具有中等偏倚风险。审查结果表明，与没有 PCOS 的孕妇相比，患有 PCOS 的孕妇发生 CI 的风险更高。这些发现强调了建立 PCOS 孕妇 CI 早期识别指南的必要性，以防止早产后孕产妇和新生儿的不良结局。