摘要目的:探讨射频消融术（radiofrequency ablation， RFA）对双绒毛膜三羊膜囊（dichorionic triamniotic，DCTA）三胎选择性减胎的安全性以及影响妊娠结局的因素。方法:采用回顾性队列研究方法收集2016年1月1日至2020年1月1日期间在南方科技大学第一附属医院深圳市人民医院产科因DCTA三胎要求RFA选择性减胎病例的患者资料，对手术经过、临床结局和并发症，以及其分娩胎盘进行分析。结果:共有12例DCTA病例纳入本回顾性分析，RFA手术时孕周为（15.6±1.3）周，分娩孕周为（36.9±1.1）周（34 +4~38 +2周）。12例中8例接受介入性产前诊断，与未接受介入性产前诊断的病例相比，两组从RFA手术到分娩的间隔差异以及分娩孕周差异均无统计学意义（ P>0.05）。共分娩新生儿23例，6例（26%）小于胎龄儿。无论是独立绒毛膜单胎还是单绒毛膜双羊膜囊（monochorionic diamniotic， MCDA）保留胎，出生体质量的平均百分位数明显低于单胎妊娠胎儿体质量的第50百分位数（ P<0.001）。1例DCTA中的MCDA保留胎RFA术后4 h死亡（8.3%），死前保留胎一度出现胎儿心动过速伴胎动消失，分娩后胎盘检查显示MCDA保留胎侧胎盘苍白而减灭胎侧胎盘瘀血。收集10例DCTA中MCDA保留胎存活的胎盘，9例可见保留胎胎盘循环通过双胎之间血管吻合支不同程度灌注了减灭胎部分胎盘小叶，1例无明显灌注减灭胎胎盘的病例MCDA保留胎体质量百分位数最低。 结论:RFA减胎对于DCTA三胎减胎安全有效，减胎后进行介入性产前诊断手术不影响RFA术后继续妊娠时间，术中监测MCDA保留胎心率和胎动异常与不良结局有关，胎盘检查有助于了解不良结局原因，保留胎生长潜能或许与双胎之间的血管吻合类型有关。

abstractsObjective:To investigate the safety of selective feticide by radiofrequency ablation (RFA) in dichorionic triamniotic (DCTA) triplets and factors related to the clinical outcome.Methods:A retrospective cohort study was designed to review the clinical records and pregnancy outcome of DCTA triplets patients who underwent RFA for selective feticide performed at the First Affiliated Hospital of Southern University of Science and Technology, Shenzhen People's Hospital from January 1,2016 to January 1,2020. Placentas were collected after delivery for gross examination and perfusion study with the mixture of vinylidene chloride and self-curing denture acrylic.Results:A total of 12 DCTA cases were recruited. Selective feticide by RFA were performed at a mean gestational age of 15.6 weeks, and cases delivered at a mean gestational age of 36.9 weeks (34 +4-38 +2 weeks). Eight of the cases undertook invasive prenatal diagnosis weeks after RFA. The interval between RFA to delivery and gestational ages at delivery were similar between women undertook prenatal diagnosis and those who did not ( P>0.05). Six of the 23 newborns (26%) were small for gestational age. The average birth weight of either monochorionic singleton fetus or the remained co-twin of the monochorionic diamniotic (MCDA) twin as lower than that of singleton pregnancy ( P<0.001). One case of DCTA (8.3%) underwent intrauterine fetal death of the MCDA co-twin 4 h after RFA. Fetal tachycardia and cessation of fetal movement of the co-twin were observed before death. By the time of delivery, placental examination revealed the pale anemia look of the placental part of the co-twin and the reddish appearance of the part of the reduced fetus, which suggested a hypovolemic shock after an uncompleted RFA as the cause of co-twin death. A total of 10 MCDA placentas from cases with a living MCDA co-twins were collected. Various degree of placental perfusion on the reduced fetal side of placenta was noticed in nine cases. The co-twin with the placenta which did not have such kind of perfusion had a birth weight at the lowest percentile. Conclusion:Selective feticide by RFA is a safe procedure for DCTA triplet, and prenatal diagnosis has no adverse impact on pregnancy outcome. Ultrasound monitoring of fetal heart rate and fetal movement of the MCDA co-twin after RFA is helpful for predicting clinical outcome. Postnatal placental examination provides clues for adverse outcome, and the growth potential of the MCDA co-twin might be related to the type of anastomosis between the two fetuses.