超声与MRI联合诊断14例单绒毛膜多胎畸形

目的 探讨超声和MRI联合诊断单绒毛膜多胎妊娠畸形的应用价值.方法 产前超声检出14例多胎妊娠畸形,均于超声检查后48 h内接受MRI检查,并于分娩或引产后证实.回顾性分析此14例的超声和MRI图象,并与随访结果比较.结果 14例多胎妊娠中无心畸胎7例、联体双胎5例、多胎之一消失2例.超声与MRI图像比较:(1)对于无心畸胎和多胎之一消失,超声可以明确诊断且是重要的随访手段;MRI能更清晰显示无心胎儿的器官与结构,并能检测供血胎儿和存活胎儿有无颅内继发改变.(2)对于联体儿,在心脏和血管结构的显示及心功能判断中超声明显优于MRI;在胃泡、肾脏、膀胱、肢体等结构的显示中超声与MRI较一致;在食管、肺、肝脏、肠管等器官的显示超声不如MRI,尤其是颅脑的显示;MRI具有较高软组织分辨力及视野大的特点,可显示较大病变及其与周围组织结构的关系,在联体双胎中可以同时显示两胎儿及两胎儿间的关系.结论 产前超声和MRI在诊断单绒毛膜多胎妊娠畸形中各有优劣,两者联合应用诊断价值更高.     

超声与MRI联合诊断14例单绒毛膜多胎畸形

目的 探讨超声和MRI联合诊断单绒毛膜多胎妊娠畸形的应用价值.方法 产前超声检出14例多胎妊娠畸形,均于超声检查后48 h内接受MRI检查,并于分娩或引产后证实.回顾性分析此14例的超声和MRI图象,并与随访结果比较.结果 14例多胎妊娠中无心畸胎7例、联体双胎5例、多胎之一消失2例.超声与MRI图像比较:(1)对于无心畸胎和多胎之一消失,超声可以明确诊断且是重要的随访手段;MRI能更清晰显示无心胎儿的器官与结构,并能检测供血胎儿和存活胎儿有无颅内继发改变.(2)对于联体儿,在心脏和血管结构的显示及心功能判断中超声明显优于MRI;在胃泡、肾脏、膀胱、肢体等结构的显示中超声与MRI较一致;在食管、肺、肝脏、肠管等器官的显示超声不如MRI,尤其是颅脑的显示;MRI具有较高软组织分辨力及视野大的特点,可显示较大病变及其与周围组织结构的关系,在联体双胎中可以同时显示两胎儿及两胎儿间的关系.结论 产前超声和MRI在诊断单绒毛膜多胎妊娠畸形中各有优劣,两者联合应用诊断价值更高.     

多胎妊娠的超声诊断

超声检查可以明确诊断是否为多胎妊娠,在15周前能100%诊断绒毛膜的情况,为后期的诊断和治疗打下基础;可以诊断胎儿畸形和其特有的畸形和异常,如联体双胎、无心畸形、双胎输血综合征等,同时在妊娠晚期也是监测胎儿生长发育的重要手段.     

产前超声诊断双胎反向动脉灌注综合征

目的 探讨多普勒超声在产前诊断双胎反向动脉灌注综合征(TRAP)中的临床价值,提高对此类罕见畸形的认识. 方法 我院1995年1月至2008年9月产前超声诊断及疑似诊断19例TRAP,比较超声与生后随访或引产后病理结果. 结果 19例TRAP中,无心畸胎(受血儿)均有严重结构畸形,产前超声对胎儿皮肤水肿、脊柱、腹腔结构及下肢显示准确性高;但对头颅发育不良及特别短小的上肢显示困难,颜面部畸形基本上显示不清.泵血儿(供血胎)中死胎及死产16例,存活3例;心功能不全9例.胎儿附属结构特征:(1)存活的无心畸胎均为脐动脉供血,血流方向朝向胎儿体内,与正常胎儿脐动脉血流方向相反;(2)两胎儿脐带胎盘附着处可见大的血管相交通;(3)无心畸胎多为单脐动脉;(4)羊水过多为预后不良征象;(5)单羊膜囊双胎常发生脐带缠绕及打结. 结论 多普勒超声可为评价TRAP血流动力学特征、评估泵血儿心功能、附属物异常及预后提供重要信息,为产前诊断TRAP的首选和重要的诊断方法.     

产前超声诊断双胎反向动脉灌注综合征

目的 探讨多普勒超声在产前诊断双胎反向动脉灌注综合征(TRAP)中的临床价值,提高对此类罕见畸形的认识. 方法 我院1995年1月至2008年9月产前超声诊断及疑似诊断19例TRAP,比较超声与生后随访或引产后病理结果. 结果 19例TRAP中,无心畸胎(受血儿)均有严重结构畸形,产前超声对胎儿皮肤水肿、脊柱、腹腔结构及下肢显示准确性高;但对头颅发育不良及特别短小的上肢显示困难,颜面部畸形基本上显示不清.泵血儿(供血胎)中死胎及死产16例,存活3例;心功能不全9例.胎儿附属结构特征:(1)存活的无心畸胎均为脐动脉供血,血流方向朝向胎儿体内,与正常胎儿脐动脉血流方向相反;(2)两胎儿脐带胎盘附着处可见大的血管相交通;(3)无心畸胎多为单脐动脉;(4)羊水过多为预后不良征象;(5)单羊膜囊双胎常发生脐带缠绕及打结. 结论 多普勒超声可为评价TRAP血流动力学特征、评估泵血儿心功能、附属物异常及预后提供重要信息,为产前诊断TRAP的首选和重要的诊断方法.     

多胎之一胎儿死亡的诊断及处理

多胎妊娠多胎之一胎儿死亡(sIUFD),存活胎儿的围产期患病率和死亡率均增加.多数胎儿死亡发生在妊娠早期,诊断主要靠早孕期超声检查提示多个孕囊,随后发现一个或多个孕囊消失.双绒毛膜双胎slUFD不会有胎儿之间的影响存在,可进行期待治疗.治疗应综合考虑病因、绒毛膜性、一胎死亡时间、母亲疾病等因素,根据母亲和胎儿具体情况作出决定.     

产前超声诊断多胎妊娠无头无心反向动脉灌注三例

目的 探讨双胎无心反向动脉灌注（twin reversed arterial perfusion TRAP）的产前超声声像图特征。方法 回顾性分析3例产前超声诊断为TRAP的超声图像与随访结果，总结声像图特点。结果 2例产后病检证实为TRAP，1例失访。TRAP的特点是，双胎或三胎中均有一个胎儿无头无心畸形，胸腹腔内没有正常内脏结构，无正常上肢结构，可见下肢及下肢运动。皮肤及皮下组织明显增厚，均为单脐动脉；彩色多普勒显示无心胎儿体内出现没有心脏的血液循环通路；频谱多普勒记录到进人胎儿体内脐血管为动脉频谱，出胎儿腹壁的脐血管为静脉频谱，形成了与正常胎儿灌注方向完全相反的灌注特点。结论 多胎妊娠中（包括双胎和三胎）若有单卵双胎，且其中之一伴有严重畸形、无心脏结构与搏动，彩色多普勒记录到进入无心胎儿体内的脐血管为动脉频谱，出胎儿的血管为静脉频谱，为TRAP的重要声像图特征。     

双胎反向动脉灌流综合征的诊治进展

双胎反向动脉灌流(TRAP)又称双胎之一无心畸形,是一种特发单绒毛膜多胎妊娠的畸形。单绒毛膜双胎妊娠中,TRAP的发生率为1/100,是双胎输血综合征(TTTS)的一种特殊类型。TRAP主要表现为双胎中一胎发育相对正常,成为供血儿(或泵血儿);另一胎为受血儿(或无心畸形),是无心脏且伴发其他严重畸形的胎儿。随着双胎TRAP诊断技术的不断提高、双胎发生率的升高以及胎儿镜技术和超声的发展,其治疗也随着发展和提高。本文就现有知识,对TRAP治疗方法的选择和结局做一个综述。     

多胎妊娠与胎儿畸形

神经管缺陷、肠道闭锁和心脏畸形等常见的先天大畸形在多胎妊娠的发生率约为 2 % ,是单胎妊娠的 2倍 ,多胎妊娠小畸形的发生率为 4 % ,是单胎妊娠的 1 6倍 ,单卵双胎或多胎的畸形发生率又较双卵或多卵多胎增加 1～ 3倍[1] ,孕妇各年龄阶段多胎妊娠的单个胎儿或多个胎儿的染色体异常出现频率也明显高于单胎妊娠。有些畸形更为多胎妊娠所特有 ,如联体畸形、无心畸形、寄生胎以及部分遗传综合征所致畸形等。1　联体畸形 (ｃｏｎｊｏｉｎｅｄｔｗｉｎｓ)如果某一卵裂球在受精后 13 5～ 15天之间 ,胚盘上 2个及 2个以上生长中心没有完全分开 ,具…     

双胎妊娠一个胎儿死亡

双胎妊娠中有10％～70％在妊娠10～16周发生一个胎儿死亡。目前共报告多胎妊娠300例产前双胎之一死亡。本文分析了43例双胎妊娠一个胎儿死亡的发生及预后。资料为14年的506例来院就诊的双胎妊娠妇女(22％为单绒毛膜双胎),均在早孕期超声确定为双活胎。一个胎儿死亡发生于孕16周     

First-trimester diagnosis of conjoined twins

Conjoined twins are a rare and complex complication of monozygotic twinning, which is associated with high perinatal mortality. Early prenatal diagnosis of conjoined twins allows better counselling of the parents regarding the management options, including continuation of pregnancy with post-natal surgery, termination of pregnancy or selective fetocide in case of a triplet pregnancy. With the introduction of high-resolution and transvaginal ultrasound imaging, accurate prenatal diagnosis of conjoined twins is possible early in pregnancy. We have reviewed the medical literature on the early prenatal diagnosis of suspected conjoined twins using a MEDLINE search. Although first-trimester diagnosis of conjoined twins is feasible, false-positive cases are common before 10 weeks because, earlier in gestation, fetal movements are limited and monoamniotic twins may appear conjoined. As most parents opt for immediate termination of pregnancy at confirmation of the diagnosis, there are limited data on the prenatal follow-up of conjoined twins. When the parents opt for conservative management, half of the fetuses die in utero and another 44% will die during the neonatal period. A detailed analysis of case reports where 3D imaging was used indicates that this modality does not improve on the diagnosis made by 2D ultrasound. Overall, very early prenatal diagnosis and first-trimester 3D imaging provide very little additional practical medical information compared to the 11-14 weeks' ultrasound examination.     

Prenatal diagnosis of thoracopagus fetus: a case report with brief review of literature

Conjoined twins are uncommon and refer to monozygotic, monoamniotic and monochorionic twins with varying degree and sites of fusion between the twins. In this report, we illustrate a case of thoracopagus twins highlighting the prenatal sonographic and magnetic resonance imaging appearance. Emphasis is laid on the role of appropriate imaging strategy in prognostic assessment and postnatal surgical treatment planning of these cases.     

Prenatal ultrasound detection of bilateral focal polymicrogyria

OBJECTIVES: Prenatal diagnosis by ultrasound of fetal polymicrogyria has been reported only once. METHODS: We describe an additional case of polymicrogyria in a fetus from a monozygotic twin pair, probably the consequence of twin-to-twin transfusion syndrome. RESULTS: On ultrasound, there were bilateral cortical hyperechogenic spots, and prenatal magnetic resonance imaging demonstrated the typical features of bilateral focal polymicrogyria. CONCLUSION: Polymicrogyria can be considered in the differential diagnosis of hyperechogenic brain lesions on fetal ultrasound. We also confirm the risk of brain damage in monochorionic twins pregnancies and the likely hypoxic-ischemic etiology of polymicrogyria.     

Two cases of pregnancy involving conjoined twins, with details of management after opting for live birth

Conjoined twinning is a unique complication of monochorionic pregnancy. This report describes the clinical findings in two cases of conjoined twins, and discusses their management. One case involved thoracopagus complicating a triplet pregnancy, and the other involved cephalothoracopagus, in which the outcome was intrauterine fetal death due to abruptio placentae after amniocentesis. Recent improvements in ultrasound imaging have facilitated the diagnosis of conjoined twins as early as the first trimester. Although many mothers opt to terminate pregnancy when conjoined twins are diagnosed, a few do not, as in the cases described. In such cases, pregnancy management, including accurate determination of the degree of organ fusion and psychological follow up, are important. On the basis of the two present cases, we present a systematic flow diagram for management of conjoined twin pregnancy from the time of diagnosis until delivery.     

The specificity of ultrasound in the detection of fetal intracranial tumors

AIMS: To evaluate the specificity of ultrasound in identifying fetal brain neoplasms and its accuracy in the diagnosis of the tumor's histological type. METHODS: A retrospective evaluation of 7 cases of fetal brain tumors occurred at our unit in the period between January 92 and June 98 has been performed. All prenatal ultrasonographic diagnoses were compared with the postnatal findings on the aborted fetuses (post-mortem examination) or on the newborns (MRI or post-mortem examination). RESULTS: In 6 out of 7 cases the antenatal ultrasonographic diagnosis of brain tumor was confirmed postnatally, in one case a supratentorial arachnoid cyst was mistaken for a teratoma with cystic components (86% specificity in the diagnosis of congenital brain neoplasms). Out of the 6 cases of suspected teratomas, one revealed to be a glioblastoma, one an arachnoid cyst and one a primitive neuroectodermal tumor. The prenatal diagnosis was confirmed in the case of choroid plexus papilloma. Prenatal ultrasonography was accurate in identifying the tumor's histological type in the 57% of the cases. The diagnoses were not modified by the transvaginal scans performed in 2 cases. CONCLUSIONS: Prenatal ultrasonography is a useful tool to identify any intracranial space-occupying lesion larger than 10 mm. In the present study it has shown an 86% specificity in the diagnosis of brain neoplasms. However the accuracy of ultrasound in diagnosing the tumor's histological type was limited (57%).     

Prenatal ultrasonographic diagnosis of thoracopagus conjoined twins

Conjoined twins are a rare obstetric event occurring 1/50,000 to 1/60,000 deliveries as a result of incomplete fission of the embryonic disc before the third week of pregnancy. They belong to the monochorionic-monoamniotic type of monozygotic twins and are classified according to the area of union, the most common site being the chest and upper abdomen (thoracopagus). Reported are two cases of thoracopagus twins in which the diagnosis was made prenatally by ultrasound in the second trimester of pregnancy. The most significant ultrasound findings included the demonstration of a single cardiac activity, the inability to separate the fetal bodies at their ventral portion, and a face-to-face fetal position. The pregnancies were allowed to continue until term with no significant prenatal complications, and an elective cesarean section was performed to avoid a traumatic delivery. In both cases the infants died during the first week of life because of cardiorespiratory insufficiency. The ultrasound criteria for the antenatal diagnosis of conjoined twins are reviewed, concluding that the careful ultrasound examination of all identified sets of twins, specially in those cases in which no separating membrane is demonstrated, is the cornerstone in making the prenatal diagnosis. In addition, ultrasound plays a crucial role not only in the diagnosis, but also in establishing the degree of conjoining, which is essential for planning an appropriate obstetrical and perinatal management.