title: The twin-twin transfusion syndrome.
abstract: Twin-twin transfusion syndrome is a complication of monozygotic-monochorionic twinning with serious perinatal implications. An extensive literature review revealed that our current understanding of the anatomy and pathogenesis of the syndrome has not changed over the last 3 decades. However, modern diagnostic modalities, such as sonography and Doppler studies, allow antenatal diagnosis and therefore may change the current definition of the syndrome. Based on these data, a new composite definition of the syndrome is suggested. This definition includes the following criteria: 1) sonographic signs (inter-twin differences in abdominal circumference greater than 18 mm, polyhydramnios-oligohydramnios, and signs of monozygosity), 2) Doppler velocimetry of the umbilical arteries (inter-twin difference in systolic/diastolic ratios above 0.4), 3) demonstration of a transplacental vascular shunt, 4) inter-twin birth weight difference of 15% or more, and 5) inter-twin hemoglobin difference of 5 g/dL or more. In addition, prenatal diagnosis may help in the management of this complication, and it seems that intrauterine treatment of the placental vascular anomalies may be more effective than other antenatal therapeutic options.
authors.affiliation: Department of Obstetrics and Gynecology, Kaplan Hospital, Rehovot, Israel.
authors.forename: I
authors.initials: I
authors.lastname: Blickstein
mesh_terms: D005260:Female; D005330:Fetofetal Transfusion / Q000000981:diagnostic imaging / Q000628:therapy; D006801:Humans; D011247:Pregnancy; D014430:Twins, Monozygotic; D016216:Ultrasonography, Prenatal