Color Difference in Placentas with Twin Anemia-Polycythemia Sequence: An Additional Diagnostic Criterion?

OBJECTIVE To determine the color intensity difference between the 2 placental shares in monochorionic placentas with twin anemia-polycythemia sequence (TAPS). METHODS We evaluated all digital pictures of TAPS placentas examined at our center and compared them to a control group of uncomplicated monochorionic placentas. We determined the color intensity of individual placental share on the maternal side of each monochorionic placenta using an image processing program and calculated the color difference ratio (CDR). RESULTS Digital pictures of 19 TAPS and 19 uncomplicated monochorionic placentas were included in this study. The TAPS group consisted of 12 spontaneous TAPS placentas (63%) and 7 post-laser TAPS placentas (37%). The median CDR in the group with TAPS was significantly higher than in the control group, 2.73 (range 1.73-6.36) versus 1.09 (range 1.00-1.35), respectively (p < 0.01). We found a positive correlation between CDR and inter-twin hemoglobin (Hb) difference in the TAPS group (R = 0.66, p < 0.01) but not in the control group (R = 0.04, p = 0.87). CONCLUSION TAPS placentas have a significantly higher CDR compared to uncomplicated monochorionic twin placentas. Large inter-twin Hb differences in TAPS are associated with higher CDR.