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.     

双胎输血综合征的预测和诊治进展

双胎输血综合征(twin-twin transfusion syndrome,TTTS)是单绒毛膜双胎妊娠的严重并发症,目前仍然是全球胎儿医学专家面临的主要挑战.在TTTS中,通过共享胎盘中的血管吻合支进行双胎输血会引起严重的血液动力学失衡,是导致围生儿死亡的主要原因.所有单绒毛膜双胎中约有10％～15％会发展成TTT...     

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.     

九例射频消融选择性减胎术的疗效及观察

目的:探讨射频消融减胎术(radio frequency ablation,RFA)对复杂性多胎妊娠的疗效.方法:回顾性分析2017年4月—2019年5月在武汉大学人民医院行RFA治疗的9例患者的临床资料,总结其临床疗效,包括流产、早产、足月产、活产、分娩方式和新生儿体质量等.结果:9例患者中有2例是双绒毛膜三羊膜囊妊...     

孕中晚期双胎之一胎死宫内存活儿预后分析

目的:分析双胎之一胎死宫内(sIUFD)后存活儿的预后。方法:回顾分析2017年1月至2019年11月在郑州大学第三附属医院分娩的sIUFD病例58例,包括sIUFD发生孕周、胎死原因、不同孕周及不同绒毛膜性存活儿的新生儿结局及脑损伤情况,并随访其神经发育情况。结果:58例孕中晚期发生sIUFD的病例中单绒毛膜双羊膜囊双胎(MCDA)27例,双绒毛膜双羊膜囊双胎(DCDA)31例。死亡原因中脐带、胎盘异常占25.9%(15/58),胎儿发育异常占5.2%(3/58);存活儿的早产率为70.7%(41/58),其中最小孕周28+1周。与DCDA双胎组比较,MCDA双胎组分娩胎龄、出生体重、Apgar评分均较低。与孕中期比较,孕晚期发生sIUFD的早产率、MCDA双胎数及急诊剖宫产率更高,新生儿出生体重、Apgar评分更低。新生儿出生后头颅超声脑异常9例,其中新生儿脑损伤3例(5.2%,3/58),分别为2例脑软化,1例脑室内出血Ⅲ级。存活儿目前的存活率为91.4%(53/58),随访时间平均28个月,3例婴幼儿智能发育量表(CDCC)监测可疑。结论:绒毛膜性、死胎发生孕周、终止妊娠的孕周是影响妊娠结局的主要因素,需加强产前、产后神经影像学检查及远期标准化随访。     

Cerebral Injury and Neurodevelopmental Outcome in Twin-Twin Transfusion Syndrome

Twin-twin transfusion syndrome (TTTS) is a severe complication of monochorionic twin pregnancies associated with high perinatal mortality and morbidity rates. Management in TTTS is a major challenge for obstetricians and neonatologists. Twins with TTTS often are born prematurely after an extremely distressing and highly hazardous fetal period. In addition to complications associated with prematurity, surviving twins with TTTS are at increased risk for other complications, including neurological, cardiovascular, renal, and hematologic morbidity. Follow-up studies report varying rates of cerebral palsy and long-term neurodevelopmental impairment. This review focuses on the cerebral injury during the neonatal period as well as long-term neurodevelopmental outcome of TTTS survivors.     

Twin pregnancy complicated by single intrauterine death. Problems and outcome with conservative management

Summary. During an 11-year period we encountered 16 pregnancies in which one twin died in utero and the pregnancy continued. Eight of these twin pregnancies were monochorionic. None of the women developed severe disseminated intravascular coagulation. The fetal outcome indicates that the prognosis for a surviving dichorionic twin is relatively good, with immaturity the main hazard. By contrast the surviving monochorionic twin has a poor prognosis with a high frequency of neurological damage. This damage is not related to intrapartum or neonatal problems and at present cannot be diagnosed before birth. There is no evidence that birth of the surviving twin by caesarean section will improve the prognosis. Early diagnosis of monochorionic twins and subsequent ultrasound follow up should identify fetal growth discrepancy and possible twin to twin transfusion requiring early delivery.     

Intrauterine fetal demise following laser treatment in twin-to-twin transfusion syndrome

OBJECTIVE: To evaluate the incidence, risk factors and consequences of intrauterine fetal demise (IUFD) of at least one twin in twin-to-twin transfusion syndrome (TTTS) treated by laser. DESIGN: Retrospective analysis. SETTING: Experience of a single centre between 1999 and 2004. POPULATION: A subgroup of 45 cases with fetal demise of one or both twins from a series of 120 cases of TTTS treated by laser. METHODS: All cases were entered prospectively into a dedicated database and the results were analysed retrospectively. MAIN OUTCOME MEASURES: Fetal demise prognostic factors, survival, fetal anaemia, brain lesions, neonatal death and intact survival. RESULTS: IUFD of one twin occurred in 40 of 120 cases (19 donors and 21 recipients). IUFD of both twins occurred in another five cases. From these 40 cases, miscarriage occurred in two and pregnancy termination was requested in another two cases because of antenatal brain lesions. Two neonates died and two presented severe morbidity, survivors were therefore neurologically normal at 6-44 months of life in 89% (32/36) of the cases. Univariate analysis showed that preoperative abnormal umbilical artery Doppler in the donor before laser treatment and in the recipient following laser treatment was associated with their demise. Incomplete coagulation was suspected in cases where anaemia or cerebral lesions developed following the death of the first twin (10). CONCLUSIONS: IUFD of one or both twins occurred in 45 of 120 (38%) cases of severe TTTS treated by laser. In these, separation of the placental circulations was incomplete in at least 22% (10/45) of the cases. Umbilical artery Doppler abnormalities before laser were found to be risk factors for the donors' demise following the procedure.     

Twin pregnancy complicated by single intrauterine death. Problems and outcome with conservative management

During an 11-year period we encountered 16 pregnancies in which one twin died in utero and the pregnancy continued. Eight of these twin pregnancies were monochorionic. None of the women developed severe disseminated intravascular coagulation. The fetal outcome indicates that the prognosis for a surviving dichorionic twin is relatively good, with immaturity the main hazard. By contrast the surviving monochorionic twin has a poor prognosis with a high frequency of neurological damage. This damage is not related to intrapartum or neonatal problems and at present cannot be diagnosed before birth. There is no evidence that birth of the surviving twin by caesarean section will improve the prognosis. Early diagnosis of monochorionic twins and subsequent ultrasound follow up should identify fetal growth discrepancy and possible twin to twin transfusion requiring early delivery.     

Management and outcome of multiple pregnancies complicated by the antenatal death of one fetus

Over a 15-year period, infants from 1,192 multiple gestations were delivered at Soroka Medical Center, Beer Sheva, Israel. In 21 patients the pregnancy was complicated by the antenatal death of one fetus. In 2 of the 4 cases of monochorionic placenta, both twins died in utero within a short time, while in the 17 cases of dichorionic placenta there was no second fetal death. It seems that in cases of monochorionic placenta, the surviving twin is exposed to a more dangerous environment, and death can occur imminently. The management protocol should be based, if possible, on the type of placentation.     

Prevalence of cranial scan abnormalities in preterm twins in relation to chorionicity and discordant birth weight

OBJECTIVE: The purpose of this study was to determine the incidence of ultrasonographically detected cerebral white matter lesions (WMLs) in preterm twins at birth in relation to chorionicity, discordant weight and twin-twin transfusion syndrome (TTTS). METHODS: In this retrospective study, perinatal, neonatal, and cranial scan data of 85 monochorionic (MC) and 94 dichorionic (DC) twin pregnancies (341 infants) delivered between 24 and 34 weeks of gestation were collected. Data were analysed according to chorionicity, discordant birth weight (>20%), single intrauterine death and TTTS. RESULTS: The cerebral WML was seen in 14% of preterm twins. Monochorionic infants had higher risks of WML than DC twin (odds ratio 7.1; 95% CI 3.28-15.8). In MC group, discordant weight (37%), TTTS (38%), single intrauterine death (67%) had higher incidence of cerebral WML than concordant weight infants (7%). Similarly, incidence of WML was higher in DC discordant compared with concordant weight infants (13% versus 2%; P < 0.05). CONCLUSION: Monochorionic infants had a seven-fold higher incidence of cerebral WML than DC infants. Discordant birth weight, TTTS and survivor of co-twin demise are an independent risk of cerebral white matter lesion.     

A study to determine the incidence of structural congenital heart disease in monochorionic twins

OBJECTIVE: To determine the incidence of structural heart disease in at least one of a monochorionic (MC) twin pair excluding any cardiac effects of twin-twin transfusion syndrome (TTTS). METHOD: A cohort study of 165 sets of MC twins undergoing detailed fetal echocardiography in a tertiary unit over a 4-year period. RESULTS: The overall risk of at least one of a MC twin pair having a structural congenital cardiac anomaly was 9.1% (15/165); for monochorionic diamniotic (MC/DA) twins, this figure was 7.0% (11/158) but for monochorionic-monoamniotic (MC/MA) twins the risk for at least one affected twin was 57.1% (4/7). If one of a pair of MC twins was affected, the risk to the other twin for a structural cardiac anomaly was 26.7% (4/15). CONCLUSIONS: The incidence of structural heart disease in MC twins is increased, independent of TTTS. This justifies referral of these pregnancies for detailed fetal echocardiography as part of their assessment. If one twin is affected, the risk to the other twin is increased further.     

Acute foeto-foetal transfusion syndrome--case report and review of the literature

The perinatal morbidity and mortality risk in monochorionic twin pregnancies are 3-5-fold increased compared to those of dichorionic twin pregnancies. Partially, this is due to the higher rate of preterm delivery but also to the twin-to-twin transfusion syndrome (TTTS). Caused by unidirectional blood flow via placental anastomoses, the TTTS leads to weight differences of more than 20% between monochorial twins. The blood donor often shows oligohydramnios, whereas the recipient shows polyhydramnios. Lewi et al. demonstrated, in a study with 202 monochorionic twin pregnancies, a 9% rate of severe TTTS. The mortality of this complication is about 90% when untreated. In contrast to the chronic TTTS, little is known about the acute intrapartal one, which is characterised by anaemia and hypovolaemia of the donor and polyglobulia of the recipient without significant weight differences between the two. In most cases, anaemia occurred after normal delivery of the first twin. Still, there are no means or signs for early detection. We describe the case of a 30-year-old primigravida with a monochorionic diamniotic twin pregnancy. During pregnancy, no evidence of TTTS could be detected. At 37 + 1 weeks gestation labour was induced with prostaglandin-containing gel. Both foetuses showed cephalic presentation. The CTG of the first twin showed a conspicuous heart rate. After labour the first twin presented with anaemia and hypovolaemic shock, the APGAR was 2/7/8. The infant's haemoglobin was 13.7 g/dL. After delivery, the second twin with APGAR 10/10/10 showed a haemoglobin of 19.6 g/dL, which is in the upper normal range. Their birth weights differed by merely 10.4%. Acute TTTS is frequently characterised by anaemia and hypovolaemia of the second twin. In our case of a monochorionic twin delivery with acute TTTS the donor was born first. Early diagnosis and neonatal intervention is essential for reducing postnatal morbidity and mortality.     

Brain damage to the survivor within 30 min of co-twin demise in monochorionic twins

Single fetal death in a twin pregnancy in the late second or early third trimester is associated with significant morbidity and mortality rate in the surviving co-twin, especially in monochorionic twin pregnancies. The common causes are twin-to-twin transfusion syndrome, chromosomal abnormalities, and congenital anomalies of the fetus or anomalies of the umbilical cord-placenta. Here we report a case of monochorionic twin pregnancy in which one fetus had a single umbilical artery (SUA) while the co-twin had two umbilical arteries. The twin with SUA died in utero at the 30th week of gestation and the other fetus was delivered by cesarean section immediately due to fetal distress diagnosed by cardiotocography. Disseminated intravascular coagulation and multicystic encephalomalacia have been observed in the surviving neonate. This case and review of the literature suggest that neurologic complication rates are also increased in monochorionic twin pregnancies with single fetal demise despite the immediate delivery as in our case.     

Multiple pregnancies with single intrauterine demise. Description of twenty-eight pregnancies

METHODS: Retrospective study of multiple pregnancies and deliveries with single intrauterine demise, in a five years' study period. RESULTS: Of a total of 13,840 deliveries in the study period, 355 represented multiple pregnancies with two or more fetuses from conception: 310 twin pregnancies and 45 triplets or higher. Twenty-eight multiple pregnancies were complicated by single intrauterine death: in six cases (group A) as first trimester spontaneous fetal loss, in nine cases (group B) due to selective fetal reduction, and in thirteen pregnancies as spontaneous intrauterine demise occurring in the second or third trimester (group C). In group A, no specific cause of death was proven. In group C, four cases of death were caused by twin transfusion syndrome, three cases by severe intrauterine growth retardation, four cases by placental insufficiency, one case by placental abruption striking one of the twins, whereas the last death was undefined. In group A, mean gestational age at delivery was 33 completed weeks. In group C, five monochorionic pregnancies were delivered at median gestational age 30 weeks and seven dichorionic pregnancies at 34 weeks (the chorionicity was indefinite in one case). The neonatal complications of the forty-two live born babies included prematurity problems only, except for one case of congenital anemia in a transfusion syndrome donor twin. None of the mothers showed signs of intravascular coagulopathy. CONCLUSION: The main problem for the surviving twin was prematurity - not the sibling's death.     

Management of twin–twin transfusion syndrome

This paper presents a review of the diagnosis and treatment of twin-to-twin transfusion syndrome (TTTS). The incidence of fetal or neonatal mortality and preterm delivery in monochorionic twin pregnancies is substantially much higher than in dichorionic twin pregnancies due to TTTS. About 15% of all monochorionic twin pregnancies are affected by severe TTTS which is characterized by hypervolemia and polyhydramnios in one fetus and hypovolemia and anhydramnios in the other one. It is caused by vascular anastomoses within the shared placental system. With close surveillance without intervention, the majority of these pregnancies result in fetal death of both fetuses. Effective treatment is provided by intrauterine laser coagulation of the communicating vessels, allowing survival of at least one fetus in about 75% of the cases.     

Maternal and neonatal outcome of twin pregnancies complicated by single fetal death.

OBJECTIVE: To study the maternal and neonatal outcome of twin pregnancies complicated by the intrauterine death of one fetus after 20 weeks of gestation. DESIGN: Retrospective, observational study of 7 twin pregnancies out of 185 twin pregnancies with the diagnosis of a single intrauterine death over a 5-years period in a university hospital. RESULTS: The incidence of single fetal death in twin gestation after 20 weeks was 3.8% in the study population with a high incidence of intrauterine growth retardation (IUGR) of the remaining fetus and preeclampsia in the further course of pregnancy. The incidence of preterm delivery was 71% with a mean gestational age of 33.0 +/- 1.0 weeks. The median interval from diagnosis of single fetal death to delivery was 10.2 +/- 4.1 days (range 1-28 days). 5 of 7 (71%) cases were delivered by cesarean section for standard obstetrical reasons. Neither perinatal nor neonatal death of the remaining twin were observed. Two cases of neurologic injury were diagnosed after delivery by ultrasound and MRI. No maternal coagulopathy related to single fetal death occurred. CONCLUSION: Expectant management of single fetal death in twin pregnancies might be advisible under close surveillance of both, mother and the surviving fetus.     

Monoamniotic twins: case series and proposal for antenatal management

Objective: To present a case series of antenatally suspected monoamniotic twin gestations managed by a similar set of guidelines.Methods: Eight women with antenatally suspected monoamniotic twins were identified between 1994 and 1996 in a single perinatal referral area. All were diagnosed sonographically. Management included serial ultrasound studies, frequent nonstress testing, and weekly steroid therapy. Elective cesarean delivery was recommended at 32 weeks unless obstetrically indicated at an earlier age.Results: Monochorionic monoamniotic twins were confirmed at delivery in six women, and one had a pseudomonoamniotic twin. One woman was found to have a monochorionic diamniotic pregnancy at delivery. Of the eight women, three were delivered by elective cesarean at 32 weeks, including the falsely diagnosed case. Three were delivered before 32 weeks because of nonreassuring fetal testing. One was delivered at 25 weeks secondary to hemolysis, elevated liver enzymes, low platelets, and disseminated intravascular coagulation. One was delivered at 33 weeks, after declining elective delivery at 32 weeks, because of death of one twin and nonreassuring testing of the other twin. Morbidity among the live-born infants included severe bronchopulmonary dysplasia (25-week twins), large-bowel perforation (30-week infant), and respiratory distress syndrome and mild bronchopulmonary dysplasia (one 32-week pair).Conclusion: Monoamniotic twin pregnancies can be diagnosed reliably by ultrasound alone in most cases. Frequent antenatal testing may show signs of cord compression that may prompt delivery but will not prevent sudden fetal death. Fetal death can occur at greater than 32 weeks’ gestation despite intensive fetal surveillance. Elective preterm delivery could be considered to eliminate the uncertain risk of fetal death.     

Ductus venosus blood flow evaluation at 11-14 weeks in the anticipation of twin-twin transfusion syndrome in monochorionic twin pregnancies

Twin-twin transfusion syndrome (TTTS) is a serious complication, occurring in about 15% of monochorionic twin pregnancies. Strong evidence suggests that increased fetal nuchal translucency thickness (NT) in one of the monochorionic twins is highly predictive of TTTS. One of the most plausible mechanisms for increased NT is heart failure, which can be indirectly manifested by abnormal blood flow in the ductus venosus. We present 20 cases of monochorionic twin pregnancies in which both NT thickness and ductus venosus blood flow evaluation were performed at 11-14 weeks. Whenever both fetuses showed discrepant NT, and abnormal ductal flow was found in the fetus with increased NT, TTTS eventually developed. In none of the twins displaying similar NT measurements, and in those with discrepant NT but normal flow in the ductus venosus of both fetuses, was the progression to TTTS observed. In the two cases that developed TTTS, fetoscopic laser coagulation of the vascular anastomoses was successfully carried out at 18 weeks, and normalization of the venous return was recorded. Increased NT and abnormal flow in the ductus venosus in monochorionic twins may be early manifestations of hemodynamic imbalance between donor and recipient The combined evaluation of both parameters in monochorionic twin pregnancies could be an effective screening method.     

Perinatal outcome and neurological follow up of the cotwins in twin pregnancies complicated by single intrauterine death

Objective

To review the outcome of twin pregnancies complicated by single fetal intrauterine death (IUD) managed at our Centre and to evaluate the neurological follow up of the surviving cotwins.

Study design

Twenty-three twin pregnancies (10 dichorionic and 13 monochorionic diamniotic) complicated by IUD in the II or III trimester were seen at our Centre during the study period (2001–2006). All patients were managed conservatively unless non-reassuring signs of fetal well-being were present at ultrasound examination or CTG after 28 weeks, suggesting immediate delivery. Serial scans after the diagnosis of single death were performed and, in addition, eight monochorionic twin pregnancies underwent prenatal MRI in order to identify the presence of cerebral lesions in the survivors. Live born surviving cotwins underwent neurological follow up.

Results

In the monochorionic group one cotwin died in utero and one in the neonatal period with a perinatal survival rate of 83.4% (10/12) (excluding one case who opted for termination of pregnancy); in the dichorionic group perinatal survival rate was 100%. In all monochorionic cases there were no signs of ischemic brain lesions in the surviving cotwins at the diagnosis of single death and during ultrasonographic follow up. In monochorionic pregnancies prenatal MRI, when performed, was negative for signs of brain damage in the surviving cotwins. Gestational age at delivery was not statistically different between monochorionic and dichorionic pregnancies (36 (range, 28.4–40.2) vs. 34.6 (range, 28.2–41.3) weeks) (p = 0.6) and the rate of early preterm delivery before 32 weeks was 23.8% (5/21) and independent from chorionicity (18.2% vs. 30%, p = 0.5). Neurodevelopmental follow up was available for 18/20 live born survivors (85%) and was normal in all but one twin; this case was born from a dichorionic pregnancy with a suspicion of congenital infection.

Conclusions

Our data confirmed a trend to a higher risk of perinatal mortality of cotwins in monochorionic twin pregnancies compared to dichorionic ones. In our experience prenatal ultrasound and MRI were useful to exclude cerebral lesions in utero and subsequent neurological sequelae in surviving monochorionic cotwins, even if definitive conclusions, especially on MRI, are limited by the small number of cases in our study.