Twin reversed arterial perfusion sequence-a rare and dangerous complication form of monochorionic twins:A case report

BACKGROUND Twin reversed arterial perfusion(TRAP) sequence is an extremely rare congenital anomaly in monochorionic(MC) twins.The condition is characterized by a malformed fetus(acardiac twin) without cardiac activities being perfused by a structurally normal one(pump twin) via an artery-to-artery anastomosis in a reverse direction.CASE SUMMARY We described the first case of TRAP to receive laser surgery in Vietnam.The 26-wk pregnancy was originally misdiagnosed in another hospital as MC twins with single intrauterine fetal death.Following admission to our center,the diagnosis was amended to a 26-wk TRAP sequence stage IIb.The acardiac twin was 7.5 cm at the longest length,the ratio of the weight of the acardiac twin to the weight of the pump twin was more than 90%,the pump twin showed fetal distress with absent diastolic flow in umbilical artery of pump twin,and the peak systolic velocity in the middle cerebral artery = 1.6 Mo M.We performed emergency laser photocoagulation of the acardiac twin’s umbilical cord.After surgery,we successfully maintained the pregnancy for 8 wk and ended it electively by cesarean section at 34 wk of gestation due to rupture of membranes.CONCLUSION TRAP should be appropriately diagnosed and treated early to avoid complications of the pump twin.Fetoscopic laser photocoagulation is a new and effective treatment for this condition.

Intrauterine Treatment of Monochorionic Triamniotic Triplet Pregnancy with Twin Reverse Arterial Perfusion Sequence

To editor:This study reports a pregnant woman who was naturally conceived with monochorionic triamniotic(MCTA)combined with twin reversed arterial perfusion(TRAP).An ultrasound revealed that one of the fetuses had a cardiac malformation,and a connection between the umbilical arteries was suspected.To reduce the acardiac fetus,radiofrequency ablation was performed at 17+3 weeks of pregnancy.At 36+4 weeks,two healthy infants were delivered via elective cesarean section.Postoperative examination revealed a direct connection between the umbilical arteries,with the placental perfusion acting as a direct pump.It is essential to identify the intrauterine status of the blood-supplying infant and vascular connections in order to achieve successful outcomes in pregnancies with complications,such as edema and heart failure.The studies involving human participants were reviewed and approved by Human Research Ethics Committee of Tianjin Central Hospital of Obstetrics and Gynecology.The patient provided her written informed consent to participate in this study.

The Umbilical Cord and Complications of Twin Gestations

The rate of twin pregnancies has increased over the last decades, largely because of the ongoing development of assisted reproductive technology and increased maternal age at childbearing. Twins have a higher risk of adverse outcomes during pregnancy and the perinatal period. The prevalence of umbilical cord abnormalities is higher for twin pregnancies compared with singleton pregnancies. Some of these abnormalities are nonspecific to twinning and can also be found in singleton gestations (such as velamentous cord insertion, vasa previa, and single umbilical artery). Other abnormalities are associated with monochorionic twins, such as umbilical cord entanglement, and umbilical proximate cord insertion. Most of these abnormalities can be detected by ultrasound evaluation. The early and accurate ultrasound diagnosis of chorionicity, amnionicity, and placental and umbilical cord characteristics is crucial if we are to predict the risk of complications and to determine the best management for twin pregnancies. Histopathological examination of the placenta and umbilical cord after delivery can help to confirm prenatal diagnosis and to provide a better understanding of the physiopathology of their abnormalities. The aim of this review was to emphasize the role that the umbilical cord plays in twin complications and to describe the management of these high-risk pregnancies.