The Correlation Between Placental Characteristics And Fetal Development In Non-TTTS Monochorionic Twins

ObjectiveIn recent years, the incidence of twins becomes more and more increased, in which monochorionic (MC) twin pregnancies accounted for a quarter. As a result of the existence of vascular anastomosis on placental surface, monochorionic twin pregnancies are complicated by twin-to-twin transfusion syndrome (TTTS), and selective intrauterine growth restriction (sIUGR), twin reverse arterial perfusion sequence (TRAPS), twin anemia polycythemia sequence (TAPS) or intrauterine demise. There are lots of studies about TTTS, in which the arteriovenous anastomosis and unequel placental sharing were considered to be the main cause. But in recent years, studies showed that in non-TTTS MC twins just like sIUGR and normal MC twins there were more complicated vascular net, which may delayed the progress of growth discordance when placenta unequally shared.In this article, we will study the placental characteristics by dye injection and literature review, helping to understand how this influences fetal growth and development.MethodsChoosing placentas from MC twin pairs delivered at obstetrics and gynecology department from Provincial hospital of Shandong University during from July in2013to February in2014. Data on placenta characteristics, including the number and type of anastomoses, the percentage of placental territory and the type of umbilical cord insertion were assessed by placental injection with colored dye.ResultsPlacental sharing discordance in all the11cases was32.73%±20.22%, and7cases had the discordance≥20%.In the all22umbilical cord insertion sites from the11cases, the rate of velamentous cord insertion was31.82%(7/22),with13.64%(3/22) marginal insertion and54.55%(12/22) central insertion. The rate of both umbilical cord were central insertion in one placenta was18.18%(2/11), with9.09%(1/11) two non-central insertion, and72.73%(8/11) were one central insertion and the other non-central insertion.There were obvious arterioarterial anastomosis in9cases (81.82%), with a mean diameter of0.16cm±0.11.The correlation analysis between neonatal birthweight discordance and placenta sharing discordance was positively relative, while no significant correlation was find with the arterioarterial anastomosis。The incidence rate of velamentous cord insertion was increased with the neonatal birthweight discordance.ConclusionPlacentas of non-TTTS monochorionic twins with birthweight discordance are more unequally shared, have a higher rate of velamentous cord insertions, but we did not find significant correlation between the fetal growth with the arterioarterial anastomosis。...