3D color Doppler of monoamniotic twin cord entanglement

Cord entanglement is a leading cause of mortality of monochorionic monoamniotic twins. Few studies focused on entanglement features/structure itself. Three-dimensional color Doppler ultrasound was conducted to evaluate the cord entanglement in monoamniotic twins at 30 weeks of gestation. Ultrasound revealed detailed features: the two cords were entangled at several points with a chain-like appearance and this complicated structure led us to closely monitor fetal well-being. Seven days later, non-reassuring fetal heart rate pattern was observed, and cesarean section was performed at 30 6/7 pregnancy week, yielding female infants without neurological sequelae. Three-dimensional color Doppler clearly delineated the features of entanglement, and thus was useful for evaluating cord entanglement in monoamniotic twins.     

Umbilical cord entanglement in monoamniotic twin preganacy--case presentation and literature review

Monoamniotic twins are at most increased risk of perinatal complications with perinatal mortality of 28-60 % reported in literature. The most specific complication to monoamniotic twins is entanglement and (or) knotting of the cords leading to intrauterine death of both (more often) or one twin. In first presented case 1, 23-year-old primigravida in 33wks of twin monoamniotic gestation was reffered to our Institute due to intrauterine death of one co-twin caused by umbilical cord entanglement. In second case, 26-year-old multigravida in monoamniotic twin gestation was admitted to our institution. A serious umbilical cord entanglement was observed and a presence of true knot of umbilical cord was suspected. Presented cases indicate that establishing a chorionicity and amniocity in twin pregnancy is an essential part of ultrasound examination. The diagnosis of cord entanglement in monoamniotic twin pregnancy enables a forecasting of possible complications. According to the established diagnosis future protocols of perinatal management could be proposed. Due to possible complications counseling and management of monoamniotic twins should be performed in tertiary medical centers.     

Endoscopic ligation of umbilical cord at 19 week's gestation in monoamniotic monochorionic twins discordant for hypoplastic left heart syndrome

We report the first attempt of reduction of monoamniotic twins, discordant for hypoplastic left heart syndrome, using a new fetoscopic technique. Employing sonographic guidance and endoscopic visualization, cord ligation was accomplished, but significant cord entanglement, not previously appreciated, resulted in the ligation of the umbilical cord of the normal fetus. Cord entanglement may frustrate endoscopic techniques in monoamniotic twins.     

Monoamniotic twins: diagnosis and management

Monoamniotic twins, although uncommon, are associated with high antenatal and perinatal morbidity and mortality. The associated complications include cord entanglement, congenital anomalies, twin-twin transfusion syndrome, intrauterine growth retardation and preterm delivery. A thorough literature search using Medline and OVID was performed to look at the current diagnostic criteria for monoamniotic twins and the subsequent management. Specific criteria are employed during ultrasonography for making the diagnosis. Different opinions in the literature exist regarding the proper antepartum monitoring of monoamniotic twins, the optimal timing and the mode of delivery. Generally, it is agreed that there should be regular antepartum fetal heart trace monitoring and serial sonograms with umbilical artery Doppler flow study. Most studies advocate delivery at 32 weeks to reduce the risk of intrauterine deaths related to cord entanglement. Cesarean section is the preferred mode of delivery even though cases of successful vaginal delivery have been reported.     

Concordant occipital encephalocele in monoamniotic twins

Anomalies occur with a greater frequency in twin gestations. Due to its multifactorial inheritance, twins are usually discordant for encephalocele. We present a case of monoamniotic twins concordant for occipital encephalocele and discordant for lung and cord anomalies.Ultrasonographic examination at 17 weeks' gestation revealed occipital encephalocele in both fetuses. The maternal serum level of alpha-fetoprotein was increased. Fetal autopsy revealed occipital encepaholocele in both twins and right pulmonary hypoplasia and one umbilical artery in one sibling. Monoamniotic twins concordant for encephalocele occur with extreme rarity. To the best of our knowledge, monoamniotic twins concordant for this neural tube defect have not been previously reported.     

Successful selective termination at 17 weeks' gestation in monochorionic monoamniotic twin pregnancy affected by twin-twin transfusion syndrome and discordant for hypoplastic left heart syndrome

OBJECTIVES: To report a successful selective feticide in a complicated monochorionic monoamniotic (MCMA) pregnancy. METHODS: A case of MCMA pregnancy with severe twin-twin transfusion syndrome and discordant for hypoplastic left heart syndrome was diagnosed at 16 weeks' gestation. A complete ultrasound and fetoscopic surveillance was performed, ruling out cord entanglement and, thus, precluding the necessity of transecting the cord. RESULTS: The selective feticide was successfully performed by bipolar coagulation of the umbilical cord of the abnormal fetus under ultrasound guidance. The survivor twin developed normally during the rest of the pregnancy and was born at term. At 6 months of age, the infant was healthy. CONCLUSION: Selective feticide in complicated monoamniotic pregnancies can be safely performed. Cord entanglement can be confidently excluded by both ultrasound and fetoscopy, thus making the systematic transection of the umbilical cord unnecessary.     

Monoamniotic twins: a retrospective controlled study

Monoamniotic twins are uncommon but are at high risk (reportedly 50%) for perinatal death, commonly from cord accidents. Until recently the diagnosis of monoamniotic twinning was seldom made before delivery, but modern ultrasound technology permits diagnosis during prenatal care, creating a management dilemma. This is a report of the experience with monoamniotic twins of 20 or more weeks' gestation at the University of Iowa Hospitals from 1961-1989. Twenty monoamniotic twin pregnancies were compared with 40 monochorionic, diamniotic controls regarding antepartum and intrapartum complications. Overall, monoamniotic twins were delivered earlier, were more likely to die in utero, and had lower birth weights than diamniotic twins. When only live-born twins were considered, however, there were no differences in gestational age at delivery, birth weight, or 5-minute Apgar scores. No fetal death occurred after 32 weeks, suggesting that prophylactic preterm delivery may not be indicated in all cases. Labor and vaginal delivery were not associated with an increased risk of fetal death.     

An Unusual Complication in a Binovular Twin Pregnancy — Umbilical Cord of Twin 2 Around the Neck of Twin 1

Summary: A case of cord entanglement involving the cord of twin 2 being around the neck of twin 1 is presented. The unusual feature of this case is that the twins were binovular, being male and female, refuting previous statements that for this complication to occur, the twins must be monoamniotic.     

Iatrogenic Monoamniotic Twins as a Complication of Therapeutic Amniocentesis

Background: Therapeutic amniocentesis has been accepted widely as a safe and efficacious way to treat the polyhydramnios-oligohydramnios sequence associated with twin–twin transfusion syndrome.Case: A 28-year-old woman, gravida 2, para 1, diagnosed with twin–twin transfusion syndrome at 28 weeks’ gestation was treated with serial amniocenteses. The dividing membrane was ruptured inadvertently during therapeutic amniocentesis, with subsequent complete disruption of the amniotic membrane. Iatrogenic monoamniotic twins with cord entanglement and knotting resulted.Conclusion: Creation of monoamniotic twins by disruption of the dividing membrane can be a complication of therapeutic amniocentesis for twin–twin transfusion syndrome. Such disruption may result in the same morbidity and mortality that are seen in naturally occurring monoamniotic twins.     

Notching of the umbilical artery waveform associated with cord entanglement in a monoamniotic twin pregnancy

Abstract

Cord accidents are the principal cause of the high rates of morbidity and mortality associated with monoamniotic twins. Observation of an umbilical artery notch might be a highly specific sign for cord entanglement involving a tight cord knot. It thus justifies the implementation of intense surveillance and should be one of the factors taken into account in deciding on early delivery of the twins.     

Entrecruzamiento de cordones en la gestación gemelar monocorial monoamniótica

Monochorial monoamniotic twins are at high risk of fetal death due to the general complications seen in multiple gestations, as well as those specific to this type of pregnancy. The most severe complication in these pregnancies is fetal death due to cord entanglement, which occurs in almost all cases.Early ultrasonographic diagnosis and intensive prenatal surveillance are essential for the early detection of cord entanglement and the prevention of fetal death.The need for in-hospital management and the exact gestational age for delivery continue to generate controversy in the literature.     

Monochorionic monoamniotic twins: neonatal outcome.

BACKGROUND: Monochorionic monoamniotic twins (MoMo) occur in one of 10,000 pregnancies. Cord entanglement, malformations, twin-to-twin transfusion syndrome (TTS) and prematurity are responsible for their high perinatal morbidity and mortality. OBJECTIVE: To report our experience with 36 sets of MoMo twins (1990 to 2005) and to provide updated information for counseling. METHODS: Chorionicity was determined by placental examination, gestational age and TTS clinically and by sonography. Intrauterine growth restriction (IUGR) was diagnosed with a twin-specific nomogram. RESULTS: Cord entanglement was observed in 15 pregnancies, but only one twin with entanglement and a true knot, experienced related morbidity. Four of 71 live births were IUGR. Malformations were diagnosed prenatally (one hypoplastic left heart and one body stalk) and postnatally (one vertebral anomalies-anal atresia-tracheoesophageal fistula-renal defect (VATER) and two lung hypoplasias). Twin-to-twin transfusion syndrome affected three sets of twins. Five twin sets delivered before 31, 19 sets at 31 to 32 and 12 sets at 33 to 34 weeks. Six of 71 (8%) twins died (four malformations, one TTS and one 26 weeks premature). Head ultrasounds in 59 of 65 survivors showed two (3%) periventricular leukomalacia, five (9%) Grade I-II intraventricular hemorrhage and 52 (88%) normal. CONCLUSIONS: Monochorionic monoamniotic twins remain a group at risk for cord entanglement, congenital malformations, TTS and prematurity. Although their neonatal mortality and morbidity is high, outcomes for survival are better than anticipated.     

Survival rates of monoamniotic twins do not decrease after 30 weeks' gestation

A search of pathology records from the years 1967 to 1988 at Women and Infants' Hospital of Rhode Island (138,232 live births) revealed 24 sets of histologically confirmed monoamniotic twins. All records were available for review. Among the 17 sets of monoamniotic twins that reached 30 weeks' gestation with at least one twin still alive, there were no further fetal deaths. The risks of early delivery in these pregnancies appear to outweigh the risk of fetal death as a result of monoamniotic status alone. These data do not show an advantage to early delivery.     

The aggressive approach to the management of monoamniotic twins

A series of five sets of monoamniotic twins are presented. The sonographic diagnostic criteria are outlined, with special emphasis on entanglement of the cord. The management protocol included: early hospitalisation, frequent sonographic, electronic fetal heart monitoring and early delivery by caesarean delivery when indicated. This management resulted in survival of all 10 neonates in the series.     

Spontaneous rupture of the dividing membrane in a monochorionic pregnancy resulting in a pseudo-monoamniotic pregnancy with cord entanglement

During pregnancy spontaneous rupture of the dividing membrane of monochorionic diamniotic twins is extremely rare and difficult to diagnose prenatally. We report a case of pseudo-monoamniotic twins derived from monochorionic diamniotic twin gestation. A 37-year-old woman pregnant with monochorionic diamniotic twins initially confirmed by the first trimester ultrasonography, was suspected to have a dividing membrane not visualized on ultrasound examinations at 27 gestational weeks. The woman did not undergo any invasive procedure during pregnancy and did not have notable symptoms. We considered the possibility of spontaneous rupture of the dividing membrane and cord entanglement, and managed the rest of her gestational period as a monoamniotic twin gestation. Concordantly grown healthy male babies were born at 35 weeks and 1 day by elective cesarean section. The mother had complex entangled umbilical cords and a small trace of amniotic membrane in the placenta.     

Cord ultrasonic transection procedure for selective termination of a monochorionic twin

Placental vascular communications can present a life-threatening problem in monochorionic twins when one fetus has a lethal anomaly. Although selective feticide is the best option for salvaging the normal twin, techniques normally employed (i.e. intracardiac potassium, air embolism) are not prudent given the common circulatory system. Furthermore, in monoamniotic, monochorionic twin gestations it is important to transect the umbilical cord completely to prevent entanglement of the dead fetus around the cord of the normal twin. We present two cases of monochorionic twins in which the cords were transected with a harmonic scalpel under ultrasonic guidance via one trocar. The harmonic scalpel is an instrument which can simultaneously coagulate and cut blood vessels or tissues. The cord ultrasonic transection procedure is a novel, minimally invasive technique which offers several advantages over the methods currently used for selective feticide in discordant monochorionic twin gestations.     

Multiple gestations: timing of indicated late preterm and early-term births in uncomplicated dichorionic, monochorionic, and monoamniotic twins

In this work we review the indications for late preterm and early-term birth in uncomplicated dichorionic, monochorionic, and monoamniotic twin gestations. Uncomplicated dichorionic twins have optimal outcomes when delivered at 38 weeks' gestation. Monochorionic twins, however, are at greater risk for unexpected stillbirth, and a management plan of late preterm delivery (34-37 weeks) after informed consent is reasonable. Monoamniotic twins are at even greater risk for sudden intrauterine fetal demise, and it is recommended that these expectant mothers be managed by inpatient hospitalization with fetal testing 1-3 times per day and delivery between 32 and 34 weeks' gestation. Recommendations are also provided for the circumstance of single intrauterine fetal demise in a twin gestation.     

Monoamniotic twin pregnancy: a review of contemporary practice

Monoamniotic twins represent an uncommon manifestation of the monozygotic twinning process (1% of monozygotic twins). They are the result of ovum division beyond 8 days postconception and are characterised by a single amnion and a single yolk sac. There may be two or one (conjoined twins) embryos present. This form of twinning is notable for an increase in perinatal loss (10-15% in contemporary series of prenatally recognised cases). Congenital anomalies, umbilical cord entanglement/accidents, preterm birth and intrauterine growth restriction primarily account for this increased perinatal mortality rate. Diagnosis is most typically by ultrasound, with the inability to distinguish a dividing membrane between the fetuses the most typical feature. There are diagnostic pitfalls (oligohydramnios in one twin with closely adherent membrane) and accuracy in diagnosis is central to appropriate pregnancy management. Obstetric management protocols are based on several retrospective case series, and there is a paucity of large well-controlled studies to provide guidance in the management of monoamniotic twin pregnancies. The prevention of antepartum death from umbilical cord entanglement is one of the central management issues; however, the available techniques of antepartum surveillance have a variable performance in predicting this event.     

Amniotic band syndrome following septostomy in management of twin-twin transfusion syndrome: a case report.

Septostomy, a rupture of the diamniotic membrane separating monozygotic twins essentially creating a monoamniotic gestation, is a potential therapeutic modality for twin-twin transfusion syndrome (TTTS). This may be associated with complications including cord entanglement or complete rupture of the membranes. We report a case of severe amniotic band syndrome with cord amputation after septostomy. A 33-year-old woman with a Mo-Di twin pregnancy was diagnosed with TTTS at 18 weeks of gestation. Septostomy as well as amnioreduction were performed at 24 weeks of gestation. A repeat cesarean delivery was performed at 31 weeks resulting in a live recipient baby of 1340 g and a dead donor with amniotic band syndrome. The donor showed pieces of membrane tightening both legs. The right thigh became entangled in the bands connecting to the umbilical cord of the live fetus. The umbilical cord of the dead twin was completely amputated, whereas the umbilical cord of the live infant was also entrapped within the amniotic band resulting in small diameter and some degree of stricture. This is the first report of a rare but serious complication following septostomy.     

Fetal asphyxia due to cord entanglement in a monochorionic diamniotic twin pregnancy complicated by 2nd-trimester single intrauterine demise

Usually, fetal asphyxia/demise because of umbilical cord entanglement and secondary cord occlusion is a unique characteristic of monoamniotic twin pregnancies. We present here a rare case of fetal asphyxia due to cord entanglement in a monochorionic diamniotic twin pregnancy complicated by 2nd-trimester single intrauterine demise. In this case, there was no amniocentesis or any other invasive intrauterine procedure performed during pregnancy.