BACKGROUND Pregnancies conceived through assisted reproduction have been associated with increased risks of adverse pregnancy and delivery outcomes, including cervical insufficiency (CI). Despite CI being a significant cause of late miscarriage or preterm birth, there are minimal published data on the associations of infertility (with or without fertility treatment) with CI. This study uses Swedish national health registers to examine the associations between infertility, assisted reproduction and CI in nulliparous women. METHODS This population-based case-control study is based on data from Swedish national health registers. Using the information on parity and multiple gestation in the Medical Birth Register, singleton pregnancies of nulliparous women were extracted and linked to the National Patient Register and the National Quality Register for Assisted Reproduction. Using diagnostic codes for CI and procedural codes for cervical cerclage, a total of 2662 CI cases were identified for deliveries in the 21-year period, 1992-2012. A reference group of 26,620 controls were extracted from the population of non-cases using simple random sampling.. Infertility was classified using a woman's report of difficulty conceiving for at least one year. Fertility treatment was assessed through self-reported variables in the Medical Birth Register and fertility treatment registration in the National Quality Register for Assisted Reproduction. RESULTS On adjusting for maternal characteristics and medical history, infertility was associated with CI, overall (adjusted odds ratio (aOR) ) 1.91 (1.53, 2.39) and in the subgroup of non-users of fertility treatment (aOR) 1.60 (1.21, 2.12), compared to women without infertility. Among women with infertility, pregnancies conceived with the aid of fertility treatment had higher risk of CI than naturally-conceived pregnancies (aOR 1.49 (1.05, 2.10). In the subgroup of women with infertility and no history of miscarriage, the use of fertility treatment was associated with CI (aOR 3.48 (2.02. 5.98)). No association was found between fertility treatment and CI in the pregnancies of women with infertility and a history of miscarriage. CONCLUSIONS From this study, we conclude that CI in nulliparous women is associated with both infertility and its treatment. For infertile women, the risk of CI following fertility treatment was seen only in those with no history of miscarriage, providing crucial information for improving risk assessment and management strategies for preterm birth prevention in populations availing of fertility treatment.

中文翻译：

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未产妇不孕与宫颈机能不全之间的关联 - 生育治疗的贡献。


背景 通过辅助生殖受孕与不良妊娠和分娩结局的风险增加有关，包括宫颈功能不全 （CI）。尽管 CI 是晚期流产或早产的重要原因，但关于不孕症（有或没有生育治疗）与 CI 关联的已发表数据很少。本研究使用瑞典国家健康登记册来检查未产妇不孕症、辅助生殖和 CI 之间的关联。方法 这项基于人群的病例对照研究基于瑞典国家卫生登记处的数据。利用医学出生登记册中关于胎次和多胎妊娠的信息，提取了未产妇的单胎妊娠，并将其链接到国家患者登记册和国家辅助生殖质量登记册。使用 CI 诊断代码和宫颈环扎术程序代码，在 2662-21 年期间（1992-2012 年）共确定了 2012 例分娩 CI 病例。使用简单的随机抽样从非病例群体中提取了 26,620 名对照的参考组。不孕症是根据女性至少一年的受孕困难报告进行分类的。通过医学出生登记册中的自我报告变量和国家辅助生殖质量登记册中的生育治疗登记来评估生育治疗。结果 在调整产妇特征和病史后，与没有不孕症的妇女相比，不孕症与 CI 相关，总体 （调整后比值比 （aOR） ） 为 1.91 （1.53， 2.39），非生育治疗 （aOR） 使用者亚组为 1.60 （1.21， 2.12）。 在不孕妇女中，借助生育治疗受孕的妊娠比自然受孕的妊娠发生 CI 的风险更高 （aOR 1.49 （1.05， 2.10）。在不孕症且无流产史的妇女亚组中，使用生育治疗与 CI 相关 （aOR 3.48 （2.02. 5.98））。未发现生育治疗与有流产史的不孕妇女妊娠的 CI 之间存在关联。结论 从这项研究中，我们得出结论，未产妇的 CI 与不孕症及其治疗有关。对于不孕妇女，生育治疗后 CI 的风险仅在无流产史的妇女中出现，这为改进利用生育治疗的人群预防早产的风险评估和管理策略提供了重要信息。