Vascular pattern in monochorionic placentas with spontaneous TAPS and TTTS with residual anastomoses after laser: a case-control study

Objective This study aimed to compare the angio-architecture of monochorionic placentas of spontaneous twin anaemia–polycythemia sequence (TAPS) with placenta of twin-to-twin transfusion syndrome (TTTS) with residual anastomoses after laser coagulation and placentas of uncomplicated monochorionic twin pregnancies. Methods This case–control study compares the angio-architecture of monochorionic placentas of spontaneous TAPS (n = 12) with that of monochorionic placentas of TTTS treated by laser coagulation with residual anastomoses (TTTS + RA; n = 20) and placentas of monochorionic pregnancies without complications (n = 24), matched for gestational age. Placental sharing and angio-architecture were assessed by injection of colored dye. Results The median diameter of the arterio-venous (AV) anastomoses in TAPS placentas was 2.26, 0.215 with TTTS + RA and 4.17 mm in normal monochorionic pregnancies (p