National Guideline Alliance, Royal College of Obstetricians and Gynaecologists, London, United Kingdom. Electronic address: LO'
Royal Cornwall Hospitals National Health Service Trust, Truro, United Kingdom.
Am J Obstet Gynecol MFM. 2020 Nov;2(4):100220. doi: 10.1016/j.ajogmf.2020.100220. Epub 2020 Sep 2.
This study aimed to determine the optimal cervical priming regimen before surgical abortion up to and including 13 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.
This study included randomized controlled trials published in English after 2000 that compared the following: (1) mifepristone and misoprostol against each other, placebo, or no priming; (2) different doses of mifepristone or misoprostol; (3) different intervals between priming and abortion; or (4) different routes of misoprostol administration.
Risk of bias was assessed using the Cochrane Collaboration checklist for randomized controlled trials, and data were metaanalyzed 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 substantial 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 Grading of Recommendations Assessment, Development and Evaluation.
A total of 18 randomized controlled trials (n=8538) were included and showed the following: decreased incomplete abortion rate (risk ratio=0.44; 95% confidence interval, 0.21-0.9) and force required to dilate the cervix (mean difference= -7.08 N; 95% confidence interval, -11.67 to -2.49) and increased preoperative bleeding (risk ratio=5.90; 95% confidence interval, 5.08-6.86) with misoprostol compared with no priming; decreased preoperative bleeding when sublingual misoprostol was given 1 hour before abortion compared with 3 hours before (risk ratio=0.14; 95% confidence interval, 0.03-0.56); and increased force required to dilate the cervix (mean difference=14.3 N; 95% confidence interval, 2.13-26.47) when mifepristone was given 24 hours before abortion compared with 48 hours before. The quality of the evidence base was limited by low event rates and risk of bias in included studies.
Cervical priming with misoprostol decreases the force needed to dilate the cervix for first trimester surgical abortion and reduces the risk of incomplete abortion. Considered alongside clinical expertise, this evidence supports the use of routine cervical priming before first trimester surgical abortion with 400 µg misoprostol or, if misoprostol cannot be used, 200 mg oral mifepristone.
本研究旨在确定在 13 周妊娠以内的手术流产前的最佳宫颈预处理方案。
对 2000 年后发表的英文文献进行 Embase、MEDLINE 和 Cochrane 图书馆检索，同时咨询专家以获取任何正在进行或遗漏的试验。
本研究纳入了比较以下干预措施的随机对照试验：（1）米非司酮和米索前列醇与彼此、安慰剂或无预处理的比较；（2）不同剂量的米非司酮或米索前列醇；（3）预处理与流产之间的不同间隔时间；或（4）米索前列醇不同给药途径。
使用 Cochrane 协作组随机对照试验清单评估偏倚风险，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%）时使用固定效应模型，当存在中度异质性（I≤50%和 <80%）时使用随机效应模型，当存在高度异质性（I≥80%）时不进行合并。当存在可用数据时，进行基于产次的亚组分析。使用 Grading of Recommendations Assessment, Development and Evaluation 评估证据的总体质量。
共纳入 18 项随机对照试验（n=8538），结果显示：与无预处理相比，米索前列醇预处理可降低不完全流产率（风险比=0.44；95%置信区间，0.21-0.9）和扩张宫颈所需的力（平均差异=-7.08 N；95%置信区间，-11.67 至-2.49），增加术前出血（风险比=5.90；95%置信区间，5.08-6.86）；与术前 3 小时相比，术前 1 小时舌下含服米索前列醇可降低术前出血（风险比=0.14；95%置信区间，0.03-0.56）；与术前 48 小时相比，术前 24 小时给予米非司酮可增加扩张宫颈所需的力（平均差异=14.3 N；95%置信区间，2.13-26.47）。纳入研究的证据基础质量受到低事件发生率和偏倚风险的限制。
宫颈预处理用米索前列醇可减少第一孕期手术流产扩张宫颈所需的力，并降低不完全流产的风险。在考虑临床专业知识的情况下，该证据支持在第一孕期手术流产前常规进行宫颈预处理，使用 400 μg 米索前列醇或如果不能使用米索前列醇，则使用 200 mg 口服米非司酮。
