Objective: This study was undertaken to report the occurrence of bipartite monochorionic twin placentas. Study design: Examination of 109 monochorionic placentas delivered at our institution between June 2002 and June...Objective: This study was undertaken to report the occurrence of bipartite monochorionic twin placentas. Study design: Examination of 109 monochorionic placentas delivered at our institution between June 2002 and June 2005 was performed. Placental characteristics on prenatal ultrasound were studied, including single or double appearance and type of intertwin membrane-placental junction (“ T" sign or lambda sign). Monochorionicity was confirmed by postnatal histologic confirmation (diamniotic intertwin membrane without chorionic tissue within the dividing septum). Bipartition was diagnosed when 2 separate placental masses attached by membranes were identified. Results: Of the 109 monochorionic placentas, 3 were composed of 2 separate placental masses. Prenatal ultrasound examination showed 2 separate placental masses in each case. Monochorionicity was suspected on prenatal ultrasound because of the presence of “ T" sign in 2 cases and twin-to-twin transfusion syndrome (TTTS)- in another case. Microscopic examination of the dividing septum was consistent with monochorionicity in each case. Vascular anastomoses were present in 2 of the 3 placentas, and led in both cases to the development of TTTS. Conclusion: Two separate placental masses in twin pregnancies are not per se dichorionic and may occur in almost 3% of monochorionic placentas.展开更多
Second-trimester twin-to-twin transfusion is well known, but first-trimester cases rarely have been described. We present the case of a monochorionic twin at 11+ 0 weeks of gestation with single increased nuchal trans...Second-trimester twin-to-twin transfusion is well known, but first-trimester cases rarely have been described. We present the case of a monochorionic twin at 11+ 0 weeks of gestation with single increased nuchal translucency and normal karyotypes. At 12+ 5 weeks of gestation, double intrauterine death was diagnosed, followed by delivery of a strikingly red and white fetus.展开更多
文摘Objective: This study was undertaken to report the occurrence of bipartite monochorionic twin placentas. Study design: Examination of 109 monochorionic placentas delivered at our institution between June 2002 and June 2005 was performed. Placental characteristics on prenatal ultrasound were studied, including single or double appearance and type of intertwin membrane-placental junction (“ T" sign or lambda sign). Monochorionicity was confirmed by postnatal histologic confirmation (diamniotic intertwin membrane without chorionic tissue within the dividing septum). Bipartition was diagnosed when 2 separate placental masses attached by membranes were identified. Results: Of the 109 monochorionic placentas, 3 were composed of 2 separate placental masses. Prenatal ultrasound examination showed 2 separate placental masses in each case. Monochorionicity was suspected on prenatal ultrasound because of the presence of “ T" sign in 2 cases and twin-to-twin transfusion syndrome (TTTS)- in another case. Microscopic examination of the dividing septum was consistent with monochorionicity in each case. Vascular anastomoses were present in 2 of the 3 placentas, and led in both cases to the development of TTTS. Conclusion: Two separate placental masses in twin pregnancies are not per se dichorionic and may occur in almost 3% of monochorionic placentas.
文摘Second-trimester twin-to-twin transfusion is well known, but first-trimester cases rarely have been described. We present the case of a monochorionic twin at 11+ 0 weeks of gestation with single increased nuchal translucency and normal karyotypes. At 12+ 5 weeks of gestation, double intrauterine death was diagnosed, followed by delivery of a strikingly red and white fetus.
