Abstract：
Labor induction abortion is effective throughout the second trimester. Patterns of use and gestational age limits vary by locality. Earlier gestations (typically 12 to 20 weeks) have shorter abortion times than later gestational ages, but differences in complication rates within the second trimester according to gestational age have not been demonstrated. The combination of mifepristone and misoprostol is the most effective and fastest regimen. Typically, mifepristone 200 mg is followed by use of misoprostol 24-48 h later. Ninety-five percent of abortions are complete within 24 h of misoprostol administration. Compared with misoprostol alone, the combined regimen results in a clinically significant reduction of 40% to 50% in time to abortion and can be used at all gestational ages. However, mifepristone is not widely available. Accordingly, prostaglandin analogues without mifepristone (most commonly misoprostol or gemeprost) or high-dose oxytocin are used. Misoprostol is more widely used because it is inexpensive and stable at room temperature. Misoprostol alone is best used vaginally or sublingually, and doses of 400 mcg are generally superior to 200 mcg or less. Dosing every 3 h is superior to less frequent dosing, although intervals of up to 12 h are effective when using higher doses (600 or 800 mcg) of misoprostol. Abortion rates at 24 h are approximately 80%-85%. Although gemeprost has similar outcomes as compared to misoprostol, it has higher cost, requires refrigeration, and can only be used vaginally. High-dose oxytocin can be used in circumstances when prostaglandins are not available or are contraindicated. Osmotic dilators do not shorten induction times when inserted at the same time as misoprostol; however, their use prior to induction using misoprostol has not been studied. Preprocedure-induced fetal demise has not been studied systematically for possible effects on time to abortion. While isolated case reports and retrospective reviews document uterine rupture during second-trimester induction with misoprostol, the magnitude of the risk is not known. The relationship of individual uterotonic agents to uterine rupture is not clear. Based on existing evidence, the Society of Family Planning recommends that, when labor induction abortion is performed in the second trimester, combined use of mifepristone and misoprostol is the ideal regimen to effect abortion quickly and completely. The Society of Family Planning further recommends that alternative regimens, primarily misoprostol alone, should only be used when mifepristone is not available.
摘要：
引产流产在妊娠中期有效。使用模式和胎龄限制因地区而异。较早的妊娠（通常12至20周）的流产时间比较晚的胎龄短。但根据孕龄，妊娠中期并发症发生率的差异尚未得到证实。米非司酮和米索前列醇的组合是最有效和最快的方案。通常,米非司酮200mg，然后在24-48小时后使用米索前列醇。95％的流产在米索前列醇给药24小时内完成。与单独使用米索前列醇相比，联合治疗方案可使流产时间在临床上显着减少40％至50％，并且可用于所有胎龄。然而,米非司酮并不广泛。因此，使用不含米非司酮（最常见的是米索前列醇或吉美前列素）或高剂量催产素的前列腺素类似物。米索前列醇更广泛地使用，因为它便宜且在室温下稳定。单独使用米索前列醇最好经阴道或舌下使用，400微克的剂量通常优于200微克或更低。每3小时给药优于频率较低的给药，尽管使用更高剂量（600或800mcg）的米索前列醇时，间隔长达12小时是有效的。24小时的流产率约为80％-85％。虽然吉贝前列素与米索前列醇相比有相似的结果，它有更高的成本，需要冷藏，只能阴道使用。大剂量催产素可用于前列腺素不可用或禁忌的情况。与米索前列醇同时插入时，渗透扩张器不会缩短诱导时间；然而，它们在使用米索前列醇诱导前的使用尚未研究。尚未系统地研究术前引起的胎儿死亡对流产时间的可能影响。虽然单独的病例报告和回顾性回顾记录了米索前列醇在孕中期诱导子宫破裂，风险的大小尚不清楚。个别宫缩剂与子宫破裂的关系尚不清楚。根据现有证据,计划生育协会建议,在妊娠中期进行引产流产时，联合使用米非司酮和米索前列醇是快速，完全流产的理想方案。计划生育协会进一步建议替代方案，主要是单独使用米索前列醇,只能在米非司酮不可用时使用。
