Screening of ultrasound markers for predicting selective fetal growth restriction in monochorionic twins at 11-13 + 6 weeks / 中华超声影像学杂志

Objective:To screen the ultrasound markers of predictive value at 11-13 + 6 weeks for selective fetal growth restriction (sFGR) in monochorionic (MC) twins. Methods:A retrospective analysis of MC twin pregnancies collected prospectively from June 2020 to December 2021 at Beijing Obstetrics and Gynecology Hospital, Capital Medical University, with standardized ultrasound examinations performed at 11-13 + 6 weeks.According to the expert consensus on the diagnostic criteria for sFGR, collected MC twin pregnancies were divided into sFGR group and control group (normal MC twin group). Maternal age, maternal history, mode of conception, the incidence of increased nuchal translucency (NT) thickness, NT discordance, crown-rump length (CRL) discordance, abnormal ductus venous Doppler waveform and abnormal umbilical cord insertion position were compared between the two groups, and those markers that differed between groups were further analyzed for screening early ultrasound markers that could be used to predict sFGR. Results:A total of 106 cases were included in the analysis, 30 cases in sFGR group and 76 cases in control group. ①Compared with control group, sFGR group had a higher incidence of low fetal birth weight (below the 10th and 3rd percentile) in both surviving cases, large birth weight discordance and a higher incidence of birth weight inconsistency (difference >25%) ( P<0.001). ②Compared with control group, the CRL discordance was larger in sFGR group [7.8% (3.8%, 9.2%) versus 3.8% (1.5%, 7.2%)] and the incidence of abnormal cord insertion position (33.3% versus 6.6%) was higher, the differences were statistically significant ( P=0.004 and <0.001, respectively), whereas the differences of NT discordance, incidence of increased NT and abnormal ductus venous Doppler waveform were not statistically significant (all P values >0.05). ③CRL discordance was a risk factor for sFGR ( OR=1.136, 95% CI=1.021-1.264), with an area under the ROC curve of 0.682 (95% CI=0.576-0.787) for predicting sFGR, the sensitivity and specificity were 0.567 and 0.737 at a cut-off value of 6.5%. Abnormal umbilical cord insertion position was a risk factor for sFGR ( OR=7.100, 95% CI=2.176-23.167) with a sensitivity of 0.333 and specificity of 0.934 for predicting sFGR. Conclusions:CRL discordance and abnormal cord insertion position are risk factors for the development of sFGR and are of value in predicting sFGR in MC twins.

Secuencia de perfusión arterial reversa en embarazo gemelar; coagulación de arteria nutricia. Reporte del primer caso en el país / Twin reversed arterial perfusion sequence; coagulation of the umbilical cord. A report on the first case in Uruguay / Seqüência reversa de perfusão arterial na gravidez gemelar; coagulação da artéria nutritiva. Relato do primeiro caso no país

Resumen: La secuencia de perfusión arterial reversa (TRAP) es una complicación muy poco frecuente y grave de los embarazos gemelares monocoriónicos. Generalmente ocurre cuando el corazón de un gemelo de apariencia normal sirve como bomba para uno o más gemelos dismórficos cuya cabeza, órganos torácicos y extremidades superiores no se desarrollan completamente o no se desarrollan en absoluto y, por lo tanto, carecen de actividad cardíaca. La arquitectura placentaria vascular anómala provoca un cambio en el flujo arterial hacia el gemelo acardíaco. Los mecanismos fisiopatológicos exactos que conducen a este fenómeno devastador no se conocen bien. Compartiremos el caso clínico de una paciente de 19 años, cursando un embarazo gemelar monocorial monoamniótico, en que realizamos diagnóstico de TRAPS, y realizamos la coagulación laser de la arteria nutricia del feto acárdico.

Abstract: Twin reversed arterial perfusion sequence (TRAPS) is rather an unusual and severe complication of monochorionic twin pregnancies. It usually occurs when the normal-appearance heart of a twin acts as a pump for one or more dysmorphic twins whose head, thoracic organs and upper limbs fail to totally develop or do not develop at all and thus, have no cardiac activity. The abnormal vascular architecture at the placenta changes the arterial flow towards the acardiac twin. The exact pathophysiological mechanisms that result in this devastating phenomenon are still unknown. The study presents the clinical case of a 19-year- old patient pregnant with monoamniotic, monochorionic twins and a diagnosis of TRAPS, treated by laser coagulation of the acardiac twin's umbilical cord.

Resumo: A seqüência reversa de perfusão arterial (TRAPS) é uma complicação muito rara e grave de gestações gemelares monocoriônicas. Geralmente ocorre quando o coração de um gêmeo de aparência normal serve como uma bomba para um ou mais gêmeos dismórficos cuja cabeça, órgãos torácicos e membros superiores não se desenvolvem totalmente ou não se desenvolvem e, portanto, não têm atividade cardíaca. A arquitetura vascular placentária anormal causa uma mudança no fluxo arterial para o gêmeo acardíaco. Os mecanismos fisiopatológicos exatos que levam a esse fenômeno devastador não são bem compreendidos. Descrevemos o caso clínico de uma paciente de 19 anos, portadora de gestação gemelar monocoriônica monoamniótica, na qual fizemos o diagnóstico de TRAPS e realizamos coagulação a laser da artéria nutritiva do feto acardíaco.

Secuencia de perfusión arterial reversa gemelar (TRAP): reporte de caso clínico de manejo expectante / Twin Reverse Arterial Perfusion Sequence (TRAP): clinical case report of expectant management

TRAP describe la perfusión crónica de un gemelo acardíaco por un gemelo de bomba a través de canales vasculares entrelazados permeables. La secuencia TRAP ocurre en 1 de cada 35.000 nacimientos o en 1 de cada 100 pares de gemelos monocigóticos. Se diagnostica mediante los hallazgos ecográficos de un feto de desarrollo normal y una masa amorfa con frecuencia con partes fetales perceptibles. El Doppler color revela el flujo sanguíneo reverso hacia el gemelo acardíaco dentro de la arteria umbilical lo que lleva a las complicaciones típicas del cuadro. El manejo expectante es razonable en ausencia de características pronósticas deficientes. El propósito de este artículo es revisar los aspectos básicos y el estado actual de esta condición, haciendo énfasis en el diagnóstico y el manejo expectante.

TRAP describes the chronic perfusion of an acardiac twin by a pump twin through permeable interlocking vascular channels. TRAP occurs in 1 in 35,000 births or 1 in 100 pairs of monozygotic twins. It is diagnosed by ultrasound findings of a normally developing fetus and an amorphous mass often with noticeable fetal parts. Color Doppler reveals the reverse blood flow to the acardiac twin within the umbilical artery, leading to typical complications of the condition. Expectant management is reasonable in the absence of poor prognostic characteristics. The purpose of this article is to review the basic aspects and current status of this condition, emphasizing the diagnosis and expectant management.

A rare case of fetus papyraceous presenting in monozygotic biamniotic twins

Fetus papyraceous or compresses is characteristic of compressed mummified, parchment like remains of dead twin retained in utero after intrauterine death in the second trimester. It is an uncommon finding and we report in a G2P1L1 with 22 weeks with Monozygoticbiamniotic twins with fetus papyraceous stuck to left upper segment followed up to 36 weeks. The mother was advised regular antenatal visits and frequent feto-maternal monitoring was done. Patient delivered a single live baby and a placenta with mummified fetus within it. The incidence of fetus papyraceous is about 1 in 17000 to 1 in 20000 pregnancies. Early diagnosis of this condition helps in monitoring the surviving fetus.

Restricción de crecimiento intrauterina selectiva tipo III, en gemelos monocoriales: serie de casos y revisión de la literatura / Monochorionic twins with type III selective intrauterine growth restriction: case series and review of the literature

We present four cases of monochorionic twin pregnancies with diagnosis of type III selective intrauterine growth restriction, highlighting the ultrasonographic characteristics (evaluation of the umbilical artery intermittent reverse diastole and the superficial arterio-arterial anastomosis), its evolution during pregnancy and its follow-up during the first month of life.

Se presenta cuatro casos de gestaciones dobles monocoriales afectadas con restricción selectiva de crecimiento de tipo III, con énfasis en las características ecográficas (evaluación de la diástole intermitente reversa de la arteria umbilical y la anastomosis superficial arterio-arterial), evolución durante la gestación y seguimiento hasta el mes de vida.

Secuencia perfusión arterial reversa: Reporte de caso / Twin reversed arterial perfusion sequence: A case report

Twin reversed arterial perfusion sequence is a complication of monochorionic twin pregnancies in which one twin that exhibits lethal anomalies, including acardia, is perfused by the other 'pump' twin via anastomoses between placental arteries. This results in growth and characteristic anomalies of the acardiac twin, and possible heart failure of the pump twin. The exact pathophysiological mechanisms that lead to this devastating phenomenon are not well known. It occurs in about 1% of monochorionic pregnancies and in one out of 35 000 pregnancies. Mortality is usually due to anemia and cardiac complications which can lead to cardiac failure, appear early during pregnancy and cause the death of the pump twin. We report a case of twin reversed arterial perfusion in a 28-year-old patient with 12 weeks monochorionic-diamniotic pregnancy that was referred for absent cardiac activity in one twin. Ultrasound showed an acardiac twin with flow reversal seen in the umbilical artery and umbilical vein and a normal second twin. At 28 weeks an emergency cesarean section was done due preterm labor and transverse situation of the second twin. The first twin was malformed and the second twin died two days later due to complications of prematurity. Accurate prenatal diagnosis of twin reversed arterial perfusion sequence is essential to improve the prognosis of this rare entity.

La secuencia de perfusión arterial reversa en gemelos es una complicación del embarazo gemelar monocoriónico, en la que un gemelo muestra anomalías mortales, incluyendo acardia, y es perfundido por el otro gemelo 'bomba' a través de anastomosis arteriales placentarias, produciendo el crecimiento y las anomalías características del gemelo acárdico, con posible insuficiencia cardíaca en el gemelo bomba. Los mecanismos fisiopatológicos exactos que conducen a este fenómeno devastador no son bien conocidos. Ocurre en aproximadamente 1% de los embarazos monocoriónicos y en 1 de cada 35 000 embarazos. La mortalidad se debe generalmente a anemia y complicaciones cardíacas que pueden conducir a insuficiencia cardíaca, que aparecen temprano durante el embarazo y causan la muerte del gemelo bomba. Se presenta un caso de perfusión arterial reversa en gemelos en paciente de 28 años de edad con un embarazo monocoriónicodiamniótico de 12 semanas quien fue referida por ausencia de actividad cardíaca de uno de los gemelos. La ecografía mostró un gemelo acárdico con reversión de flujo visto en arteria-vena umbilical y un segundo gemelo normal. A las 28 semanas se realizó una cesárea de emergencia debido a parto pretérmino y situación transversa del segundo gemelo, obteniendo el primer gemelo marcadamente malformado y un segundo gemelo vivo que murió dos días después de las complicaciones de la prematuridad. El diagnóstico prenatal exacto secuencia de perfusión arterial reversa en gemelos es esencial para mejorar el pronóstico de esta rara entidad.

Resultados périnatales en embarazos múltiples monocoriales relacionados con las características placentarias / Perinatal outcomes in monochorionic multiple pregnancies regarding the placental characteristics

Resumen OBJETIVO: evaluar las características placentarias de pacientes con embarazos múltiples monocoriales relacionados con el resultado obstétrico en nuestro medio. MATERIAL Y MÉTODO: estudio observacional, descriptivo, prospectivo efectuado en dos instituciones de tercer nivel de atención de Bogotá, Colombia, entre el 31 julio de 2009 y el 31 de agosto de 2011. Evaluación de pacientes con embarazos monocoriales, complicaciones, tratamientos y resultados perinatales; análisis placentarios relacionados con el número y tipo de anastomosis, forma y distancia entre las inserciones de los cordones umbilicales y distribución placentaria. RESULTADOS: se incluyeron 72 embarazos monocoriales: 93.1% correspondieron a embarazos dobles y 86.1% a biamnióticos. De las placentas analizadas, 91.6% tuvieron al menos una anastomosis, específicamente arterioarterial (70.8% de los casos). Se encontraron complicaciones propias de los embarazos monocoriales (41.6%), principalmente: restricción de crecimiento intrauterino selectivo (16 casos) y trasfusión feto-fetal (11 pares de gemelos). Se registró un caso de trasfusión arterial reversa y una muerte fetal (10.7%) provocada por síndrome de transfusión feto-fetal. Entre las causas de morbilidad neonatal se encontraron: taquipnea transitoria del recién nacido y enfermedad de membrana hialina. La mortalidad neonatal fue de 5.4%. No hubo casos de mortalidad materna. CONCLUSIÓN: las características placentarias determinan las complicaciones propias del embarazo monocorial, principalmente: síndrome de trasfusión feto-fetal, restricción de crecimiento intrauterino selectivo. La detección ecográfica prenatal de estas alteraciones es importante para ofrecer consejería y vigilancia gestacional programada.

Abstract OBJECTIVE: To evaluate placental characteristics in monochorionic multiple pregnancies in relation to obstetric outcome in our environment. MATERIAL AND METHOD: Prospective and observational study was made; carried to 31 July 2009 and 31 August 2011 in two high complexity institutions in Bogota, Colombia. We included monochorionic pregnancies for diagnosis of complications, management and perinatal outcome, placental analyzes were evaluated with respect to the number and type of anastomosis, type and distance between umbilical cord insertions and placental sharing. RESULTS: We registrered 72 monochorionic pregnancies, twin pregnancies were 93.1% and 86.1% diamniotic. Placentas analyzed 91.6% had at least one placental anastomosis, arterio-arterial mainly in 70.8% of patients. Complications of monochorionic pregnancies in 41.6% of cases mainly selective growth restriction in 16 cases, followed by twin to twin transfusion in 11 pairs of twins were found. A case of blood transfusion reverse was presented; and a fetal mortality of 10.7% remains the leading cause twin to twin transfusion syndrome. Among the causes of neonatal morbidity transient tachypnea of the newborn, followed by hyaline membrane disease were found. The neonatal mortality rate was 5.4%. There were no maternal deaths. CONCLUSION: Placental characteristics determine the complications of monochorionic pregnancy, as the presence of twin to twin transfusion syndrome selective growth restriction and perinatal outcome. Prenatal sonographic identification of these features is important for prenatal counseling and the frequency of gestational surveillance.

Prognosis for Monochorionic Twins with Twin Reversed Arterial Perfusion Sequence / 中山大学学报(医学科学版)

[Objective] The purpose of this study was to evaluate the association of ultrasound findings and different treatments with the prognosis of the pump twin in twin reversed arterial perfusion sequence (TRAP).[Methods] The 55 cases that were diagnosed as TRAP during the period from January 4th 2010 and August 31st 2015 were included.Ultrasound appearances of monochorionic twins were documented in detail when the twins were diagnosed with TRAP initially.At the initial evaluation,presence or absence of the following abnormalities were documented,including the ratio of the acardiac twin to the weight of the pump twin,hydrops fetalis in the pump twin,cardiomegaly in the pump twin,polyhydramnios in the pump twin,oligohydramnios in the acardiac twin and different treatments.The relationship between these ultrasound characteristics and different treatments with mortality of pump twin were analyzed with logistic regression.[Results] A total of 55 cases with TRAP were diagnosed in our institution and three cases were lost to follow up.Selective reduction was performed in 21 cases,termination of pregnancies in 13 and expectant management in 18.Excluding the cases that underwent termination of pregnancy,the remaining 39 cases were divided into two groups according treatment,expectant management group (n=18) and selective reduction group (n=21).Overall survival rate of the pump twin in these two groups was 66.7％ and 71.4％,respectively,P =0.748.The markers of perinatal outcome were not significantly different between expectant management group and selective reduction group.Logistic regression demonstrated that cardiomegaly in the pump twin (OR=21.73,95％CI:1.15 ～ 203.89,P ＜ 0.001) were significant correlated with mortality of the pump twin.[Conclusion] The prognosis markers were not significantly different between conservative management and selective reduction group.Cardiomegaly in the pump twin should be considered as risk predictors for mortality of the pump twin in TRAP.

Resultados perinatales en el síndrome de transfusión feto fetal manejados con la técnica de Solomon: revisión de la literatura / Perinatal outcomes in fetal-fetal transfusion syndrome managed with the Solomon technique: literature review

INTRODUCCIÓN: Entre 15-20% de los embarazos gemelares monocoriales biamnióticos se complican con el síndrome de transfusión feto/fetal el cual se asocia con mortalidad superior a 90% y morbilidad significativa en el 50% del gemelo sobreviviente. La técnica láser que coagula la superficie de la placa coriónica entre los principales canales a lo largo del ecuador (técnica de Solomon), se ha sugerido para disminuir la recurrencia, prevenir complicaciones secundarias sin incrementar resultados adversos. Métodos: REVISIÓN de la literatura existente en las bases de datos MEDLINE, EBSCO, OVID, PROQUEST, COCHRANE, Lilacs, SciELO, desde el año 2000 al 2015. Se incluyeron los artículos de revisión e investigaciones originales que compararon la técnica estándar de fotocoagulación secuencial con láser y la técnica de Solomon, el resultado primario fue la reducción de la incidencia Secuencia Anemia Policitemia, recurrencia del síndrome de transfusión feto/fetal, mortalidad perinatal y morbilidad neonatal severa. RESULTADOS: Se encontraron 200 artículos, se seleccionaron seis: 1 ensayo clínico y su análisis secundario, 2 estudios de cohorte retrospectivos, 1 revisión sistemática y un estudio que compara los resultados del neurodesarrollo. Los estudios sugieren una mejoría en la sobrevida de algunos de los fetos con la técnica Solomon, menor recurrencia del síndrome de transfusión feto/fetal y Secuencia Anemia Policitemia, sin la presencia de eventos adversos. CONCLUSIÓN: La técnica de Solomon mejora la sobrevida de algunos gemelos, sin embargo no puede concluirse que haya mejoría en la mortalidad pues los estudios no tienen el suficiente poder para determinarlo.

INTRODUCTION: Between 15 to 20% of monochorionic diamniotic twin pregnancies are complicated by the twin-twin transfusion syndrome. It has a mortality greater than 90% and a significant morbidity, 50% in the surviving twin. The Solomon technique (laser photocoagulation of the main vascular channels of the chorio-nic plate surface along the entire vascular equator) has been suggested to reduce the recurrence, and pre-vent secondary complications without increasing adverse results. METHODS: Systematic review of electronic searches of the literature from 2000 to 2015 (MEDLINE, EBSCO, OVID, PROQUEST, COCHRANE, Lilacs, and SciELO). We included review articles and original investigations comparing the standard photocoagulation technique with laser ablation against the Solomon technique. The primary results were reduction of Anemia Polycythemia Sequence incidence, twin-twin transfusion syndrome recurrence, perinatal mortality and severe neonatal morbidity. RESULTS: Of 200 articles, we selected six: one clinical essay and its secondary analysis, two retrospective cohort studies, one systematic review and a study comparing neurodeve-lopmental outcomes. The studies suggested a survival improvement in some fetuses using the Solomon technique, less twin-twin transfusion syndrome recurrence and Anemia Polycythemia Sequence without the presence of adverse effects. CONCLUSION: Solomon technique improves the survival of some twins, although we cannot conclude there is mortality improvement, because the studies do not have enough power to determine that.

Restricción selectiva del crecimiento intrauterino en la gestación gemelar monocorial: diagnóstico y manejo / Selective intrauterine growth restriction in monochorionic-diamniotic twins: diagnosis and management

La Restricción Selectiva del Crecimiento Intrauterino se produce en 10 a 19% de los gemelos monocoriónicos, y se asocia con un aumento importante de la mortalidad y la morbilidad perinatal. La evolución clínica está dada en gran parte por la presencia de anastomosis vaculares y la distribución placentaria asimétrica. Se propuso una clasificación en tres tipos según el Doppler de la arteria umbilical del gemelo más pequeño, la que sé que se correlaciona con distintos comportamientos clínicos y características de la placenta, lo que ayuda en el asesoramiento y conducta obstétrica. Los del tipo I tienen un pronóstico favorable por el resultado perinatal satisfactorio por lo que se recomienda un seguimiento cercano por ecografía y Doppler. Los de tipo II tienen un mal pronóstico y el tipo III un pronóstico intermedio e impredecible. En estos dos últimos se puede realizar un manejo expectante hasta que se observe deterioro del feto pequeño, considerando la posibilidad de la coagulación con láser o la oclusión del cordón (feticidio selectivo). Ambas conductas aparentemente aumentan las posibilidades de supervivencia del feto de peso normal.

Selective intrauterine growth restriction occurs in 10-19% of monochorionic twins, and is associated with increased mortality important and perinatal morbidity. The clinical course is given largely by the presence of placental vascular anastomosis and asymmetric distribution. It classified into three types according to the proposed Doppler umbilical artery smaller twin, the one that correlates with different clinical behaviors and characteristics of the placenta, which helps in counseling and obstetric conduct. The type I have a favorable prognosis for satisfactory perinatal outcome so closely monitored by ultrasound and Doppler is recommended. The type II has a poor prognosis and type III intermediate and unpredictable prognosis. In these last two you can make an expectant management until deterioration of the small fetus is observed, considering laser coagulation or cord occlusion (selective feticide). Both behaviors appear to increase the chances of survival of the fetus of normal weight.

Restricción selectiva del crecimiento intrauterino (RCIUs)

La restricción de crecimiento intrauterino selectivo es una complicación de la gestación monocorial poco frecuente, caracterizada por el déficit de crecimiento de uno de los fetos, fenómeno que se explica principalmente por la distribución asimétrica del territorio placentario. La influencia de las anastomosis vasculares determina el tipo de evolución de cada caso. El estudio Doppler de la arteria umbilical del feto con restricción es la mejor maneja de valorar el comportamiento clínico y la posible evolución, con la finalidad de minimizar el riesgo de muerte intraútero y el daño cerebral que podrían sufrir ambos fetos.

Selective intrauterine growth restriction is arare complication of monochorionic gestation characterized by growth deficiency of one fetus, phenomenon due to asymmetric distribution of the placental territory; the influence of the vascular anastomosis determines the type of evolution in each case. Umbilical artery Doppler study ofthe restricted fetus determines the clinical status and possible outcome in order to minimize risk of intrauterine death and brain da mage in both fetuses.

Twin Reversed Arterial Perfusion Sequence (TRAP Sequence). The Acardiac / Acephalic Twin.

Twin-Reversed Arterial Perfusion (TRAP sequence) is a rare complication of monochorionic twins (MC, twins sharing one placenta). TRAP sequence is known as acardius or chorioangiopagus parasiticus. It occurs in 1% of monochorionic twin pregnancies and in 1 in 35,000 pregnancies. The risk of recurrence was estimated 1:10,000. TRAP sequence is characterized by a structurally normal pump twin perfusing an anomalous twin. In TRAP syndrome, there is mortality and deformities in both twins. The acardiac/acephalic twin is a parasitic twin that fails to develop a head, arms and a heart. The parasitic twin is with or without legs, receives its blood supply from the host twin (Pump twin). In TRAP sequence, one twin is usually developmentally normal (pump twin) and the other twin has a serious condition, either missing a heart (acardiac) or a head (acephalic) or both, that prevents it from surviving on its own. The acardiac/acephalic twin receives all of its blood from the normal or “pump” twin. The abnormal fetus does not have a heart; all of its blood must come from the normal twin. And it is kept alive by the blood which is pumped from the normal twin through the placenta. The term “reversed perfusion” is used to describe this scenario because blood enters the acardiac/acephalic twin through reversed flow through its umbilical artery and exits through the umbilical vein, which is opposite to the normal blood supply of the fetus.The acardiac twin loses direct vascular connection with the placental villi and receives its entire blood supply from the pump twin [1,2,3,4]. Proper timing of the delivery is of prime importance for the survival of the normal fetus. The emphasis is placed on close sonographic monitoring from early antenatal diagnosis. The mortality of the acardiac twin is 100%, and the perinatal mortality of the pump twin is reported to be around 50%. The mortality rate of the pump twin appears to correlate with the size of the acardiac twin and primarily due to congestive heart failure. We present such a case of TRAP sequence because of its rarity. TRAP sequence, was diagnosed by ultrasound at the obstetrics and gynecology department at KAMS & RC (Kamineni) and it was closely followed up until delivery. Clinical presentation, ultrasound findings, outcome and management were reviewed in present article.

Twin-to-Twin Transfusion Syndrome: Diagnosis and Managements / 대한주산의학회잡지

Twin-to-twin transfusion syndrome (TTTS) is a severe complication of monochorionic twin pregnancies, characterized by the development of unbalanced chronic blood transfer from one twin, defined as donor twin, to the other, defined as recipient, through placental anastomoses. The incidence of TTTS in monochorionic diamniotic gestations is approximately 10% to 20%. The natural history of severe TTTS is well established with mortality approaching 80% to 100% if left untreated, especially when it presents at less than 20 weeks' gestation. This review presents overview of what is known about the pathophysiology and the diagnosis of TTTS, the markers for early detection of TTTS, treatment options available for TTTS, and complications of treatment for TTTS.

Selective fetoscopic laser photocoagulation of superficial placental anastomoses for the treatment of severe twin-twin transfusion syndrome

OBJECTIVE: To report our initial institutional experience with fetoscopic laser photocoagulation of placental anastomoses in severe twin-twin transfusion syndrome using a 1.0 mm endoscope. METHODS: Between July 2006 and June 2008, 19 monochorionic diamniotic twin pregnancies complicated by severe TTTS (Quintero stages III and IV) underwent fetoscopic laser therapy. Perinatal data were prospectively collected and compared according to the Quintero stages. RESULTS: Nine patients were classified as stage III and ten as stage IV. The Mean gestational ages at diagnosis and procedure were 20 (range: 17-25) and 22.0 (range: 19.0-26.0) weeks, respectively, with no statistical difference between the two groups. Preterm premature rupture of the membranes occurred in two cases (10.5 percent), and spontaneous preterm delivery in eight (42.1 percent). Overall mean gestational age at delivery was 32.1 (range: 26.0-38.0) weeks. Prematurity was more severe in stage IV patients (p<0.01). Among all cases, the overall survival rate was 52.6 percent, and the percentages of pregnancies with survival of both babies and at least one twin were 26.3 percent and 78.9 percent, respectively. In the case of stage III patients, the overall survival rate was 61.1 percent. Of the stage III pregnancies, 33.3 percent resulted in both babies surviving, and 88.9 percent of these pregnancies resulted in at least one surviving twin. For stage IV, as the corresponding statistics were 45.0 percent, 20.0 percent and 70.0 percent respectively. CONCLUSIONS: Our initial institutional experience with 1.0 mm fetoscopic laser therapy for severe TTTS showed results similar to those reported in the literature for larger endoscopes.

Selective Termination Procedures in Monochorionic Pregnancies / 대한주산의학회잡지

Monochorionic pregnancies have placental anastomoses that to varying degree create a common circulation. This presents unique challenges for the performance of selective termination in cases of acardiac twin, twin to twin transfusion syndrome, or discordant twin abnormalities. Multiple methods of interrupting the affected twin's circulation have been attempted with variable success.

A Case of Successful Selective Abortion Using Radio-frequency Ablation in Twin Pregnancy Suffering from Severe Twin to Twin Transfusion Syndrome

Twin to twin transfusion syndrome (TTTS) is one of the major complication of monochorionic twin pregnancy which is mainly understood by placental vascular anastomosis. Perinatal mortality and morbidity is high as 80-100% if untreated and even higher if the disease is developed at early stage. Variety of methods of isolating or intercepting placental vascular anastomosis are introduced, but they are only available in centers where all the required equipments are prepared. We report here a case of TTTS complicated with severe polyhydroamnios during the second trimester. The blood supply to donor twin was interrupted successfully at 19+2 weeks of gestation by minimally invasive radio-frequency cord ablation, under ultrasound guidance. The normal recipient twin was delivered successfully at 35 weeks of gestation and had no eventful neonatal course.

A Case of Successful Selective Abortion Using Radio-frequency Ablation in Twin Pregnancy Suffering from Severe Twin to Twin Transfusion Syndrome

Twin to twin transfusion syndrome (TTTS) is one of the major complication of monochorionic twin pregnancy which is mainly understood by placental vascular anastomosis. Perinatal mortality and morbidity is high as 80-100% if untreated and even higher if the disease is developed at early stage. Variety of methods of isolating or intercepting placental vascular anastomosis are introduced, but they are only available in centers where all the required equipments are prepared. We report here a case of TTTS complicated with severe polyhydroamnios during the second trimester. The blood supply to donor twin was interrupted successfully at 19+2 weeks of gestation by minimally invasive radio-frequency cord ablation, under ultrasound guidance. The normal recipient twin was delivered successfully at 35 weeks of gestation and had no eventful neonatal course.