Medical Abortions 药物流产

　　Medical abortion medications

　　药物流产使用的药物

　　Mifepristone is a progesterone antagonist derived from norethindrone that promotes decidual necrosis, cervical softening, increased uterine contractility, and prostaglandin sensitivity. Misoprostol is a prostaglandin E1 analogue that causes uterine contractions and cervical softening.

　　米非司酮是一种从炔诺酮研发的孕酮拮抗剂，可以促进蜕膜坏死，宫颈软化，增加子宫收缩性和前列腺素敏感性。米索前列醇是一种前列腺素E1类似物，可引起子宫收缩和宫颈软化。

　　Regimens

　　使用方案

　　FDA-approved regimen

　　FDA批准的方案

　　The only regimen approved by the Food and Drug Administration (FDA) in the United States is 600 mg of mifepristone administered orally, followed by misoprostol 400 mcg administered orally 48 hours later. The efficacy of the regimen is 92% up to 42 days of gestation. This regimen is not routinely recommended or used.

　　FDA管理局批准的唯一方案是先口服600mg米非司酮，然后在48小时后口服400mcg米索前列醇。这种方案在妊娠42天之前使用的有效性为92%，但一般不使用这个方案。

　　Evidence-based regimens

　　循证方案

　　Other evidence-based regimens are considered superior to the FDA-approved regimen for both efficacy and safety. The most successful regimen consists of mifepristone 200 mg orally, followed by misoprostol 800 mcg, taken buccally, vaginally, or sublingually 24-48 hours later with success rates of 95% - 99% up to 63 days gestational age (1). An alternative option with similar success rates is the use of vaginal misoprostol 800 mcg six hours or less after taking mifepristone (2). A recent study also demonstrated a success rate of 93% among women 63-70 days gestational age (3).

　　其他循证方案在疗效和安全性方面被认为低于FDA批准的方案。最成功的方案是口服米非司酮200mg，在24-48小时后通过口服，阴道给药或舌下含服800mcg米索前列醇，这种方案对妊娠不超过63天的患者的成功率是95%至99%(1)。另一种方案是在服用米非司酮6小时或更短时间内使用阴道给药米索前列醇800mcg，这两种方案成功率类似(2)。近期一项研究发现，妊娠在63-70天的女性使用这种方案的成功率为93%(3)。

　　Adverse events

　　副作用

　　Bleeding and cramping are normal side effects of medical abortion. Adverse effects are typically mediated by dose and route of misoprostol. These include nausea, vomiting, diarrhea, headaches, dizziness, and low-grade fevers. Oral or sublingual administration more commonly results in gastrointestinal side effects as compared to vaginal and buccal routes. Adjunct medications – non – steroidal anti-inflammatory drugs (NSAIDs), narcotics, and anti-emetics – may be helpful in mediating side effects.

　　出血和腹痛是药物流产的正常副作用。不良反应通常与米索前列醇的使用剂量和方式有关，包括恶心，呕吐，腹泻，头痛，头晕和低烧。与阴道和口腔给药相比，口服或舌下给药导致胃肠道副作用的几率更高。辅助药物例如非甾体抗炎药，麻醉剂和止吐药可能有助于缓解副作用。

　　Follow –up

　　随访

　　Follow-up is required to confirm that the abortion is complete. Ultrasound has traditionally been the gold standard to confirm expulsion of the gestational sac. It is normal to see blood products and deciduas on ultrasound, and in the absence of excessive bleeding, these findings do not represent need for uterine evacuation (4).

　　患者需要随访以确认妊娠完全终止。超声波检查是确认孕囊已排出的金标准。在超声图上看到血液物和蜕膜是正常的，在患者没有过度出血的情况下，不需要做清宫手术(4)。

　　Prerequisite follow-up ultrasound may be a barrier to medical abortion for some women. Assessing symptomatology in conjunction with hCG level is an accurate way of ensuring completion of the procedure while minimizing the number of in-person visits (3, 4). An 80% decrease in serum hCG values one week after abortion is highly correlated with completed abortion and results in fewer surgical interventions than ultrasound follow-up.

　　虽然超声检查是确认妊娠终止的必要条件，但有些患者可能不方便做超声检查。这种情况下，结合患者的症状和血清hCG水平也可以准确评估妊娠是否终止，且能最大限度减少患者随访次数(3，4)。在药物流产一周后血清hCG水平下降80%，说明妊娠基本终止了，只需要再做超声确认，需要手术再干预的可能性降低。

　　References

　　参考文献

　　1. von Hertzen H, Huong NT, Piaggio G, et al. Misoprostol dose and route after mifepristone for early medical abortion: a randomized controlled noninferiority trial. BJOG 2010 Sep; 117(10):1186-96.

　　2. Creinin MD, Fox MC, Teal S, et al. A randomized comparison of misoprostol 6 to 8 hours versus 24 hours after mifepristone for abortion. Obstet Gynecol 2004 May;103(5 Pt 1):851-9.

　　3. Winikoff B, Dzuba IG, Chong E, et al. Extending outpatient medical abortion services through 70 days of gestational age. Obstet Gynecol 2012 Nov; 120(5):1070-6.

　　4. Clark W, Bracken H, Tanenhaus J, et al. Alternatives to a routine follow-up visit after medication abortion: a systematic review. Contraception 2011 Jun;83(6)”504-10.