选择性减胎术在中期妊娠的应用

目的　探讨选择性减胎术在中期妊娠的应用及其注意事项。　方法　对 19例多胎妊娠孕妇在妊娠 12～ 2 5周行选择性减胎术。其中双胎 6例 ,三胎 11例 ,四胎、六胎各 1例。在超声引导下经腹向胎儿心内或胸腔内注入高浓度的氯化钾。　结果　 6例双胎除 1例单绒毛膜双胎外均获减胎成功 ;11例三胎 ,除 1例减胎后计划生育引产 ,1例单卵三胎外 ,9例中 7例减胎成功 ,2例减胎后流产 ;1例四胎减胎成功 ;1例六胎减胎后流产。　结论　选择性减胎术可成功应用于妊娠中期 ,母亲无严重的并发症 ,但有一定的流产率。如果减胎术前能排除单卵双胎或单卵三胎 ,或能选择近宫底的妊娠囊进行减胎 ,或能将被减胎儿的羊水抽尽 ,或推迟减胎的时间 ,可能会降低流产率。     

辅助生殖后中孕期多胎妊娠减胎相关问题

辅助生育技术增加多胎妊娠,通过限制胚胎移植数目及取消卵巢高反应周期,高数目多胎妊娠的风险在减少。因多胎妊娠母儿风险增加,有些情况下选择性中期妊娠减胎术是必要的。减胎术一般保留至2个胎儿,减胎后妊娠成功率随初始胎儿数的增加而降低。绒毛膜性的确定对于围产期管理至关重要。中期妊娠减胎术的手术方法根据绒毛膜性不同而选择药物注射或脐带血管闭塞法。辅助生殖技术也增加单绒毛膜双胎的发生。当单绒毛膜双胎发生血管吻合异常和胎盘共享不均时,可能导致不良结局,为复杂性双胎。多胎妊娠减胎可优化孕妇和留存胎儿的健康状况,但少数可能发生整个妊娠丢失。应正确把握减胎指征,尊重孕妇和家属的知情选择。     

复杂性双胎妊娠中射频消融减胎术的应用

复杂性双胎妊娠发生一胎胎死宫内时，由于胎儿间存在大量的交通血管，可能导致另一胎儿的急性失血、低血压休克和死亡，故部分单绒毛膜双羊膜囊并发症患者需行选择性减胎术，以降低存活胎儿的脑损伤风险。目前射频消融是应用较多的一种技术，本文介绍了射频消融减胎术的原理、手术过程及围手术期处理和手术并发症，并与其他常见减胎手段进行比较。     

多胎妊娠中孕期选择性减胎术

中孕期妊娠选择性减胎术主要目的是减少多胎妊娠胎儿数、减灭异常胎儿,改善多胎妊娠结局。在排除单绒毛膜双胎的情况下,药物减胎比较成熟和安全,一般在妊娠 11～24 周实施,妊娠成功率接近自然双胎。对于单绒毛膜双胎采用血管闭塞的技术进行选择性减胎,国内多采用射频消融,一般选择在15～27周。手术适应证、手术时机、手术方法以及术者的熟练程度与妊娠结局有关。减胎术前应行超声检查判断绒毛膜性、诊断早期胎儿异常和识别双胎特殊并发症。     

双绒毛膜多胎妊娠不同孕周选择性减胎术后临床结局分析

目的:探讨双绒毛膜多胎妊娠不同孕周选择性减胎术后的临床结局。方法:回顾性分析2012年1月至2018年12月98例双绒毛膜多胎妊娠于四川大学华西第二医院进行选择性减胎术的临床资料,根据实施减胎术孕周分为3组:G1组(孕14~19+6周,19例)、G2组(孕20~27+6周,30例),G3组(≥孕28周,49例),比较不同孕周行选择性减胎术后的临床结局。结果:①98例中行选择性减胎术原因包括染色体异常(25例)、胎儿结构畸形(68例)及其他母胎合并症(5例)等。②G1组母体无相关并发症发生;减胎术后2周G2组母体发生胎膜早破2例,宫内感染2例;G3组发生胎膜早破4例,宫内感染2例。③减胎术后流产发生率为8.2%、早产发生率为50.0%,活产儿存活率94.6%。3组分娩孕周差异无统计学意义(P>0.05)。G1组流产率显著低于G2组(10.5%vs 20.0%,P<0.05);G1组的活产儿出生体质量及存活儿出生体质量也优于G2组(P<0.05);G1组的早产率、足月产率、活产儿出生体质量及存活儿出生体质量均优于G3组(P<0.05)。结论:在孕20周前对双绒毛膜多胎妊娠行选择性减胎术,其妊娠结局较好,合理使用选择性减胎技术,可以有效减灭异常胎儿和多胎妊娠的胎儿数量,减少多胎妊娠的并发症及合并症,改善多胎妊娠母胎结局。     

双胎妊娠适宜的分娩时机与分娩方式

双胎妊娠的分娩仍是产科最具挑战性的事件。双胎妊娠的分娩时机与分娩方式应根据孕周、当地的医疗条件（产科条件是否为区域性医疗中心、新生儿重症监护病房救治水平等）及母胎的具体情况（绒毛膜性,有无并发症或合并症、复杂双胎等,甚至患者经济情况）等综合考虑,制定适宜的个体化分娩方案。对于无并发症及合并症的双绒毛膜双羊膜囊双胎,38～39+6周分娩较适宜;对于无并发症及合并症的单绒毛膜双羊膜囊双胎,适宜的分娩时机为37～38周;复杂性双胎（如单羊膜囊双胎、双胎输血综合征、选择性胎儿生长受限、贫血-红细胞增多序列征、单绒毛膜双胎减胎术或宫内治疗后）,需结合孕妇及胎儿的具体情况制定个体化的分娩方案,分娩时机为32～36周。双胎择期剖宫产指征包括单羊膜囊双胎、连体双胎（除外早中孕者）、第一胎非头位、具有单胎的剖宫产指征者,除此之外,均可考虑阴道分娩。     

多胎妊娠延迟分娩15例临床分析

目的:探讨多胎妊娠延迟分娩的临床处理及母胎近远期结局。方法:回顾性分析2010年1月至2018年9月四川大学华西第二医院发生的多胎妊娠延迟分娩15例的临床资料。结果:15例中1例单绒毛膜双羊膜囊双胎,1例双绒毛膜三羊膜囊三胎,1例三绒毛膜三羊膜囊三胎,余均为双绒毛膜双羊膜囊双胎。第一胎儿平均分娩孕周为28周。延迟分娩平均间隔时间为5.2天,延迟胎儿平均分娩孕周为29周,延迟胎儿平均出生体质量1294.6 g。延迟胎儿共17个,死胎、死产3个,活产儿14个,存活新生儿8个。15例共32个胎儿活产23个,存活12个,存活儿平均分娩孕周31~(+5)周,出生体质量为1672 g,存活儿中1例发生脑白质软化,余预后良好。15例中发生宫内感染2例,母体败血症1例,胎盘胎膜残留4例,胎盘早剥2例,母体肺水肿1例,母体上消化道出血1例。结论:当多胎妊娠第一胎儿流产或早产后,密切监测母胎状况下,严格掌握指征,实施延迟分娩,可延长未娩出胎儿孕周,改善延迟胎儿围生结局。     

多胎妊娠妇女孕中期选择性减胎术的临床应用

目的 通过对多胎妊娠妇女于孕中期行选择性减胎术,研究其手术指症、时机、安全性、目标胎儿的选择标准和减灭胎儿数,探讨选择性减胎术在改善多胎妊娠结局中的作用.方法 对37例孕12周+1～25周多胎妊娠孕妇(6例双胎、21例三胎、8例四胎、2例五胎,共117个胎儿)在超声引导下经腹行选择性减胎术,按产科医疗指征,在拟被减的46个胎儿心脏内注射10%氯化钾2～5 ml,见胎心逐渐减慢至停跳视为减胎术成功.术后定期产前检查和监测凝血功能,记录妊娠期并发症及妊娠结局.结果 (1)成功率:共减去胎儿46个,减胎成功率为100%(46/46个胎儿),已有27例孕妇分娩,获24个健康新生儿,妊娠成功率为88.9%(24/27).(2)分娩孕周:＞36周分娩者15例;32～36周7例;28～32周3例;＜28周流产者2例;正在妊娠中10例.平均分娩孕周(34.9±4.1)周,孕28周后分娩率为92.6%(25/27).(3)新生儿平均出生体重:单胎妊娠新生儿平均出生体重为(3014±640)g,双胎妊娠为(2557±573)g,三胎妊娠中除1例两个胎儿存活(出生体重分别为1400及1500 g)外,其余均死亡.(4)安全性:除2例单羊膜囊双胎在减灭1个胎儿后,另1个胎儿随即死亡外,其余多胎妊娠妇女的保留胎儿均未发生胎死宫内.(5)并发症:37例多胎妊娠妇女中仅3例发生子痫前期,减胎术后均无凝血功能障碍发生.(6)阴道流血:有13例孕妇减胎术前发生阴道流血,其中1例在妊娠13周强烈要求减胎,减胎术后于孕22周流产;另12例均在阴道流血停止1周以上后施行减胎.结论 (1)孕中期选择性多胎妊娠减胎术,可以有效减少多胎妊娠胎儿数目、避免异常胎儿出生,降低孕产妇并发症,提高新生儿出生体重.(2)胎儿保留数目以达双胎为好.(3)减胎术前有阴道流血者,避免在流血期间减胎,应选择在流血停止1周以上进行.(4)孕中期多胎妊娠减胎术不会造成孕妇的凝血功能障碍,也不会造成保留胎儿的宫内死亡,安全性好;减胎术后子痫前期的发病率明显下降.     

妊娠中晚期双绒毛膜双胎一胎胎死宫内妊娠结局分析

目的：比较双绒毛膜双胎之一选择性减胎与自发一胎胎死宫内（single intrauterine fetal death,SIUFD）的围生期结局,并比较不同减胎孕周对围生期结局的影响,探讨选择性减胎的临床应用。方法：纳入2011年1月—2019年12月在南京大学医学院附属鼓楼医院产科终止妊娠的55例双胎之一胎死宫内或行选择性减胎术将双胎减至单胎的临床资料,根据减胎或死胎原因将其分为选择性减胎组（39例）和自发SIUFD组（16例）,回顾性分析比较其围生期结局。结果：55例患者总妊娠丢失率为9.1%（5例流产）,活产率为90.9%。选择性减胎组的减胎/死胎孕周明显低于自发SIUFD组,总体终止孕周、活产率明显高于自发SIUFD组,而剖宫产率、流产率则低于自发SIUFD组,差异均有统计学意义（P<0.05）。2组的早产率、足月产率、存活儿出生体质量、出生体质量百分位数、新生儿健康出院率、新生儿重症监护病房（neonatal intensive care unit,NICU）入住率比较,差异均无统计学意义（均P>0.05）。根据选择性减胎的孕周将选择性减胎组再分为减胎孕周≤20周组（24例）和减胎孕周>20周组（15例）,2组新生儿出生体质量百分位数比较差异无统计学意义（P>0.05）,但与减胎孕周>20周组比较,减胎孕周≤20周组的早产率低、足月产率高,存活儿出生体质量更高,差异有统计学意义（均P<0.05）。结论：双胎妊娠发生SIUFD后会对存活儿围生期结局产生不良影响,对于有减胎指征者,选择性减胎有利于提高存活儿围生期的活产率及改善新生儿结局,对多胎妊娠的围生期结局有益。     

辅助生殖技术单卵双胎相关因素分析及含单绒毛膜双胎三胎妊娠减除单绒毛膜双胎之一的临床结局比较

目的探讨辅助生殖技术(ART)治疗后行多胎妊娠减胎术中单卵双胎(MZT)的发生和三胎妊娠行单绒毛膜双胎中一胎减胎术保留双胎者的临床结局。方法回顾性分析ART治疗后行经阴道多胎妊娠减胎术的196例患者的临床资料,分析比较MZT在不同分组中的发生情况,同时比较其中伴单绒毛膜双胎的三胎妊娠减单绒毛膜双胎之一者(A组)与不伴单绒毛膜双胎的三胎妊娠减胎后保留双胎者(B组)的临床结局。结果 (1)196例患者中MZT所占比率为44.39%(87/196)。MZT占比率在体外受精(IVF)组(0.85%)、卵胞质内单精子显微注射(ICSI)组(0.66%)、冻融胚胎移植(FET)组(0.78%)和人工授精(AIH/AID)组(0.16%)间比较差异有统计学意义(P=0.001);在辅助孵化(AH)组(1.48%)和无AH组(0.44%)间比较差异亦有统计学意义(P=0.000)。MZT占比率在高龄(≥35岁)和非高龄患者中(P=0.330)及卵裂期胚胎移植组和囊胚期胚胎移植组组间(P=0.950)比较差异无统计学意义。(2)A组和B组患者的平均年龄、平均孕周、新生儿的平均胎龄、平均胎儿出生体质量、流产率、早期流产率、晚期流产率、早产率、足月产率、活产率、低出生体质量儿发生率、新生儿出生缺陷率和妊娠并发症率比较,差异均无统计学意义(P0.05)。结论 ART行多胎妊娠减胎术的患者中MZT所占几率很高,为减少MZT的发生,尽量选择单胚胎移植;A组和B组患者临床结局无统计学差异,单绒毛膜双胎中一胎减胎术可能是安全而可行的。     

173例多胎妊娠选择性减胎术后的围生结局

目的:分析多胎妊娠选择性减胎术后的围生结局。方法:回顾性分析2012年1月至2015年9月间173例多胎妊娠孕妇在广州医科大学附属第三医院胎儿医学中心通过经腹胎儿心内注射氯化钾(KCL)减胎术或射频消融(RFA)减胎术将多胎妊娠减至单胎或双胎的临床资料,分析减胎术后的围生结局。结果:KCL减胎术121例,术后流产率为10.0%,围生儿存活率89.2%。孕早期的流产率、≤34周早产率与孕中期比较,差异无统计学意义(P0.05);保留单胎的分娩孕周较保留双胎的延长约2周(37.96±2.65周vs 35.93±2.19周)且新生儿体质量更重(2.91±0.55 kg vs 2.51±0.44kg),差异有统计学意义(P0.05)。RFA减胎术52例,术后围生儿存活率为71.2%。双胎输血综合征(TTTS)、选择性胎儿生长受限(s FGR)、双胎反向灌注序列综合征(TRAPs)、双胎之一结构或遗传异常术后的存活率分别为68.2%、83.3%、100.0%、53.8%。结论:KCL减胎术可在孕早中期进行,减至单胎可能更有益于围生结局。RFA减胎术中s FGR和TRAPs术后的存活率较高。选择性减胎术对改善多胎妊娠的围生结局有益。     

双胎妊娠分娩时机与分娩方式的选择

近年来,双胎妊娠发生率急剧上升,双胎分娩的处理是具有挑战性的临床问题。双胎妊娠分娩方式与分娩时机应结合母胎情况、当地医疗机构医疗水平和医疗条件进行综合考虑。无并发症单绒毛膜双羊膜囊(monochorionic-diamniotic,MCDA)双胎分娩不超过37周为宜,双绒毛膜双羊膜囊(dichorionic-diamniotic,DCDA)双胎可妊娠至38周,单绒毛膜单羊膜囊(monochorionic-monoamniotic,MCMA)双胎为32～33周分娩。对于无并发症MCDA双胎与DCDA双胎可考虑阴道试产,MCMA双胎则建议剖宫产手术终止妊娠。     

Mode of delivery and neonatal outcome in uncomplicated monochorionic twin pregnancies

Objective: The association between of mode of delivery and perinatal morbidity in monochorionic (MC) twins is not clear. Thus there is no agreement regarding the optimal mode of delivery of MC twins. The aim of this study is to determine the impact of the mode of delivery on neonatal outcome of uncomplicated MC twins in a tertiary center with a strict policy of delivering MC twins by 37 weeks’ gestation. Methods: Retrospective analysis of all uncomplicated MC twin deliveries at a tertiary referral hospital during a 5-year period. Complicated MC pregnancies (fetal death, selective reduction, twin to twin transfusion syndrome, fetal growth restriction of one or both twins or major fetal anomalies) were excluded. Induction of labor or planned caesarean sections of uncomplicated MC pregnancies was conducted between 35 and 37 weeks of gestation. Neonatal outcomes of MC twins were compared according to the mode of delivery. Moreover, mode of delivery was compared with a control group of 1934 dichorionic (DC) twin pregnancies delivered during the same period. Results: The rate of Caesarean section was 63.4% in uncomplicated MC/DA twins pregnancies and this was similar to our rate in DC twins (61%, p = 0.65). Multivariate analysis revealed that adverse neonatal outcome was significantly associated with gestational age at delivery, neonatal birth weight discordance and male gender but not with the intended or actual mode of delivery. Conclusion: Delivering MC twin pregnancies by 37 weeks’ gestation is associated with similar rate of vaginal deliveries compared with DC twin pregnancies. The neonatal outcome was not affected by the mode of delivery, and therefore vaginal delivery seems safe in MC twins.     

Radiofrequency ablation for selective reduction in complex monochorionic multiple pregnancies: A case series

Objective

To determine the safety and efficacy of radiofrequency ablation (RFA) for selective fetal reduction in complex monochorionic multiple pregnancies.

多胎妊娠孕中期减至双胎与初始双胎妊娠的妊娠结局比较

目的 探讨多胎妊娠孕妇孕中期行减胎术减至双胎后与初始双胎孕妇的妊娠结局比较.方法 选择2007年8月至2010年9月在山东大学附属省立医院妇产科门诊或住院、多胎妊娠孕妇567例,其中双胎妊娠孕妇478例为非减胎组;妊娠12周以后在本院实施孕中期减胎术(在超声引导下经腹的胎心内氯化钾注射法),由初始多胎减至双胎的孕妇89例为减胎组.减胎组孕妇中,初始三胎70例,初始四胎13例,初始五胎及以上6例.观察两组孕妇年龄、分娩孕周、妊娠并发症、新生儿出生体质量及新生儿结局.结果 (1)两组孕妇年龄及分娩孕周:非减胎组与减胎组孕妇平均年龄分别为(29.7±4.5)和(29.9±5.0)岁,两组比较,差异无统计学意义(P=0.755).非减胎组与减胎组孕妇平均分娩孕周分别为(35.3±3.9)和(34.4±6.3)周,两组比较,差异有统计学意义(P＜0.01).分娩孕周＜28周者(即流产)在非减胎组发生率为6.3％( 30/478),在减胎组为15.7％( 14/89),两组比较,差异有统计学意义(P=0.002).(2)两组妊娠并发症:子痫前期发生率在非减胎组及减胎组分别为8.2％ (39/478)和12.4％(11/89),两组比较,差异无统计学意义(P=0.199);妊娠期糖尿病发生率在非减胎组及减胎组分别为1.7％(8/478)和3.4％( 3/89),两组比较,差异无统计学意义(P =0.287).(3)两组新生儿情况:①非减胎组两个胎儿出生体质量差值＞400g的发生率为28.9％(138/478),减胎组为27.0％ (24/89),两组比较,差异无统计学意义(P=0.715).非减胎组两个胎儿出生体质量差值＞100g的发生率为75.1％(359/478),减胎组为75.3％(67/89),两组比较,差异无统计学意义(P =0.972).②非减胎组新生儿平均出生体质量为(2700 ±468)g,明显高于减胎组的(2352 ±602)g,两组比较,差异有统计学意义(P＜0.01).非减胎组＞孕36周+1 分娩的新生儿平均出生体质量为(2809 ±424)g,减胎组为(2707±506)g,两组比较,差异有统计学意义(P＜0.01).③减胎组及非减胎组＞28孕周分娩新生儿的死亡率分别为1.3％( 1/78)和2.2％( 10/448);减胎组及非减胎组新生儿患病率分别为3.8％ (3/78)和4.0％ (18/448),两组＞28孕周分娩的新生儿死亡率及患病率分别比较,差异均无统计学意义(P =0.588、0.943).结论 多胎妊娠减胎至双胎的妊娠结局较初始双胎者差,其流产率较高;多胎妊娠减胎后分娩孕周受初始胎儿数的影响,新生儿出生体重质量低于初始双胎.     

Discordant lower urinary tract obstruction in early twin gestations: management and outcome

OBJECTIVE: To report our experience with the management of twin pregnancies discordant for lower urinary tract obstruction. METHODS: Cases of twin pregnancies discordant for lower urinary tract obstruction were identified from our fetal medicine database. Information on ultrasonographic findings, antenatal course, pregnancy complications, and perinatal outcome was obtained by reviewing medical records or contacting the referring obstetricians. RESULTS: Five twin pregnancies discordant for lower urinary tract obstruction were diagnosed between 11 and 15 weeks of gestation. There were 3 dichorionic and 2 monochorionic pregnancies (1 diamniotic and 1 monoamniotic). The dichorionic pregnancies were managed conservatively, resulting in a pregnancy loss of both twins in 1 case, a single fetal death at 29 weeks in 1 case, and an early neonatal death due to lung hypoplasia of the affected twin in 1 case. On the other hand, both monochorionic twin pregnancies were managed with serial vesicocenteses. In both cases, the prenatal course was complicated, 1 by premature rupture of the membranes and the other by cord entanglement, requiring delivery at 29 and 31 weeks, respectively. Among the 4 continuing pregnancies with complete perinatal outcome, none of the affected twins survived, and the structurally normal twins were delivered between 29 and 36 weeks and discharged from the hospital in good condition. CONCLUSION: Twin pregnancies discordant for lower urinary tract obstruction are at high risk of perinatal death and premature delivery. Prenatal intervention seems not to be associated with an improved perinatal outcome of the affected twin, but it may be beneficial in selected cases to attain viability of the unaffected twin.     

First-trimester fetal reduction to a singleton infant or twins: outcome in relation to the final number and karyotyping before reduction by transabdominal chorionic villus sampling

OBJECTIVE: The purpose of this study was to evaluate fetal outcome and maternal complications of multifetal pregnancy reduction to a single fetus or twins. To evaluate safety and efficacy of transabdominal chorionic villus sampling for karyotyping before fetal reduction. STUDY DESIGN: Four hundred twenty-four consecutive multiple pregnancies were reduced to twins (255 pregnancies) or a single fetus (169 pregnancies) at 8 to 13 weeks of gestation after transabdominal chorionic villus sampling for fetal karyotyping. Fetal and maternal outcome were observed prospectively and compared with control series of twin (147) and singleton (885) pregnancies in which reduction procedures were not performed. RESULTS: Transabdominal chorionic villus sampling was performed successfully in 100% of the cases. The accuracy of karyotyping was 99.2%. The overall pregnancy loss rate after reduction was 3.3%. No differences were observed between study and control series for severe prematurity, low birth weight, and neonatal deaths. Mean gestational age at delivery (35.2% vs 38.1%) and mean birth weight (2180 g vs 2873 g) were significantly lower; preterm delivery (64% vs 11%), neonatal death (3.4% vs 0.6%), and maternal complications (42.8% vs 9.5%) were significantly higher when the reduction was to twins rather than in reduction to a single fetus. Pregnancy loss rate did not differ between study series. The overall rate of chromosomal abnormalities in the study series was higher (relative risk, 2.0) than in singleton control series. CONCLUSION: The outcome of multiple pregnancies that were reduced to a single fetus or twins was similar to that of nonreduced pregnancies; fetal and maternal complications were significantly lower in the series of pregnancies that were reduced to a single fetus. The safety and efficacy of transabdominal chorionic villus sampling and the higher pregnancy rate of chromosomal abnormalities in multiple pregnancies imply that fetal karyotyping should be advised before fetal reduction.     

Perinatal outcome and management of single fetal death in twin pregnancy: a case series and review

OBJECTIVE: To determine neonatal outcome of single fetal death in twin pregnancy. METHODS: Retrospective study was performed on 30 cases of single fetal death in twin pregnancy during the period from August 1971 to December 1997 at Kitasato university hospital. RESULTS: The incidence of single fetal death in twin pregnancy was 6.2% among total number of 481 twins. Prognosis of surviving infants was satisfactory except in one case, with malformation in 10 cases of dichorionic twins (total 242 sets). In contrast, neonatal death occurred in 6 cases of 20 monochorionic twins (total 239 sets), 4 of which were among 7 cases of twin-to-twin transfusion syndrome (TTTS). Cerebral palsy occurred in 2 infants of monochorionic twins. One case was diagnosed as periventricular leukomalacia (PVL) within one week after birth, and this was the case of delivery 1 day after one twin fetal death. CONCLUSION: Single fetal death itself occurs more often in monochorionic twins. There seems to be a benign outcome for the surviving dichorionic twins. On the other hand, there may be a grave outcome, though infrequent, for monochorionic twins when concomitant TTTS has existed. It is very important to identify the chorionicity by ultrasound examination in early pregnancy.     

Clinical evaluation of the risk of twin-to-twin transfusion syndrome using the relative power contribution of fetal heart rate fluctuations

OBJECTIVES: In twin pregnancies, it has been suggested that fluctuations of the two fetal heart rates should be considered as two variates that affect each other. We therefore investigated whether the relative power contribution (RPC) of heart rate fluctuation between twins reflects the clinical severity of twin-to-twin transfusion syndrome. STUDY DESIGN: Sixty-three cases of twin pregnancy including 43 monochorionic twins and 20 dichorionic twins were studied. Thirteen monochorionic twins with polyhydramnios in one twin were regarded as twin-to-twin transfusion syndrome (TTTS). Of the 13 TTTS cases, 8 cases with polyhydramnios in one twin and oligohydramnios in the other were deemed to be a 'stuck' twin. The RPC of the very low frequency domain (VL; 0.0125-0.0625 Hz) of fetal heart rate fluctuation in the twin fetuses of monochorionic and dichorionic pregnancies was obtained within a week of delivery. The relationship between the value of the RPC and the outcome of these twins was examined. RESULTS: For both monochorionic and dichorionic twins the RPC of twin fetuses was significantly higher in TTTS twins than in twins without TTTS. In particular, in pregnancies that resulted in fetal death, early neonatal death, or hydrops of one of the twins, this twin had a higher RPC than the other twin. No significant difference was observed in the RPC value between twins of either monochorionic or dichorionic pregnancies that did not develop TTTS. Serial changes in RPC values were followed in 7 cases of TTTS. The RPC value rose rapidly just before delivery in three cases with resultant poor outcome. CONCLUSION: A rapid change in the RPC of twin fetuses measured using the VL frequency domain of fetal heart rate fluctuations may predict poor outcome in twin pregnancies.