National Guideline Alliance, Royal College of Obstetricians and Gynaecologists, London, United Kingdom. Electronic address: LO'
British Pregnancy Advisory Service, Stratford-upon-Avon, England, United Kingdom.
Am J Obstet Gynecol MFM. 2021 Jan;3(1):100283. doi: 10.1016/j.ajogmf.2020.100283. Epub 2020 Nov 28.
This study aimed to determine the optimal cervical priming regimen before surgical abortion between 14 and 24 weeks' gestation.
Embase, MEDLINE, and the Cochrane Library were searched for publications up to February 2020. Experts were consulted for any ongoing or missed trials.
Randomized controlled trials, published in English after 1985, that compared (1) mifepristone, misoprostol, and osmotic dilators against each other, alone or in combination; (2) different doses of mifepristone and misoprostol; (3) different intervals between priming and abortion; or (4) different routes of administration of misoprostol were included.
Risk of bias was assessed using the Cochrane Collaboration checklist for randomized controlled trials, and data were meta-analyzed in Review Manager 5.3. Dichotomous outcomes were analyzed as risk ratios using the Mantel-Haenszel method, and continuous outcomes were analyzed as mean differences using the inverse variance method. Fixed effects models were used when there was no significant heterogeneity (I<50%), random effects models were used for moderate heterogeneity (I≤50% and <80%), and evidence was not pooled when there was high heterogeneity (I≥80%). Subgroup analyses were undertaken based on parity where available. The overall quality of the evidence was assessed using Grades of Recommendation Assessment, Development, and Evaluation.
A total of 15 randomized controlled trials (N=2454) were included and showed decreased difficulty of procedure and/or increased cervical dilation and decreased patient acceptability with regimens that included dilators compared with those that did not include dilators; increased preoperative expulsion of the pregnancy with sublingual misoprostol and mifepristone compared with sublingual misoprostol alone; increased difficulty of procedure with dilators and misoprostol compared with dilators and mifepristone; decreased difficulty of procedure with dilators and mifepristone compared with dilators alone; and increased cervical dilation when dilators were placed the day before abortion compared with the same day.
Considered alongside clinical expertise, the published data support the use of osmotic dilators, misoprostol, or mifepristone before abortion for pregnancies at 14 to 16 weeks' gestation; osmotic dilators or misoprostol for pregnancies at 16 to 19 weeks' gestation; and osmotic dilators alone or with mifepristone for pregnancies at 19 to 24 weeks' gestation. The effectiveness of pharmacologic agents alone beyond 16 weeks' gestation and the optimal timing of dilator placement remain important questions for future research.
本研究旨在确定 14 至 24 周妊娠期间行手术流产前最佳的宫颈预处理方案。
截至 2020 年 2 月，检索了 Embase、MEDLINE 和 Cochrane 图书馆的文献。为了寻找任何正在进行或遗漏的试验，还咨询了专家。
随机对照试验，1985 年后以英文发表，比较（1）米非司酮、米索前列醇和渗透扩张器单独或联合使用；（2）不同剂量的米非司酮和米索前列醇；（3）预处理与流产之间的不同间隔；或（4）米索前列醇的不同给药途径。
使用 Cochrane 协作组对随机对照试验的清单评估偏倚风险，并使用 Review Manager 5.3 进行荟萃分析。二分类结局采用 Mantel-Haenszel 法分析风险比，连续结局采用方差倒数法分析均数差。当无显著异质性（I<50%）时，采用固定效应模型；当存在中度异质性（I≤50%和<80%）时，采用随机效应模型；当存在高度异质性（I≥80%）时，不进行数据合并。根据可用的产次进行亚组分析。使用推荐评估、制定与评价分级系统评估证据的总体质量。
共纳入 15 项随机对照试验（N=2454），结果显示与不使用扩张器的方案相比，包含扩张器的方案可降低手术难度和/或增加宫颈扩张，并降低患者接受度；与单独使用米索前列醇相比，舌下含服米非司酮和米索前列醇可增加术前妊娠排出率；与米非司酮和扩张器相比，扩张器和米索前列醇增加手术难度；与扩张器和米非司酮相比，扩张器和米索前列醇增加宫颈扩张；与同日放置相比，扩张器放置在流产前一天可增加宫颈扩张。
综合临床专业知识，已发表的数据支持在 14 至 16 周妊娠时使用渗透扩张器、米索前列醇或米非司酮；在 16 至 19 周妊娠时使用渗透扩张器或米索前列醇；在 19 至 24 周妊娠时使用单独的渗透扩张器或米非司酮。单独使用药物在 16 周后是否有效，以及扩张器放置的最佳时机，仍是未来研究的重要问题。
