Differential postnatal cardiovascular course of donor-recipient twins and associated pathophysiology—a cohort study

Fetal echocardiography in twin-to-twin transfusion pregnancies treated with photocoagulation noted impaired cardiac function. Systematic information about cardiac structure or function and arterial distensibility after birth is not available. This study evaluated cardiovascular function and arterial dynamic properties in survivors of twin-to-twin transfusion syndrome (TTTS). Eleven pairs of donor-recipient twins were compared with each other and with 20 singletons of comparable gestational age. The twin cohort was born at 31.5 ± 2 wk gestational age; birthweights of donors-recipients were comparable (donors: 1,358 ± 421 g vs. recipients: 1,617 ± 460 g, <i>P</i> = 0.2). Significant intertwin differences were noted for cardiac function parameters. Recipients had greater septal thickness (donors: 2.3 ± 0.15 vs. recipients: 2.7 ± 0.36 mm, <i>P</i> = 0.01) and globularity [lower sphericity index (donors: 1.76 ± 0.1 vs. recipients: 1.62 ± 0.12, <i>P</i> = 0.009)]. They also had lower cardiac function [tricuspid annular plane systolic excursion (donors: 4.6 ± 0.5 vs. recipients: 4.1 ± 0.4 mm, <i>P</i> = 0.02) and right ventricular fractional area change (donors: 30 ± 1 vs. recipients: 27.7 ± 1.3%, <i>P</i> = 0.0001)]. Compared with singletons, differences were statistically more significant for recipients. Arterial distensibility however was more affected in donors [higher arterial wall stiffness index (donors: 2.5 ± 0.2 vs. recipients: 2.2 ± 0.2, <i>P</i> = 0.008) and lower pulsatile diameter (donors: 51 ± 5 vs. recipients: 63 ± 10 µm, <i>P</i> < 0.0001)]. Compared with singletons, the differences were statistically more significant for donors. Evaluation in the neonatal period noted that cardiac function and arterial distensibility are affected in TTTS twins. These cohorts will benefit from close postnatal follow-up for the evolution of cardiac and arterial impairments.<b>NEW & NOTEWORTHY</b> Evaluation for fetuses with twin-to-twin transfusion syndrome noted impaired cardiac function in recipients. Systematic data after birth are lacking. We noted greater ventricular dilatation, globularity, and hypertrophied interventricular septum in the recipient. Right ventricular contractility was reduced; differences between recipients-singletons had greater statistical significance compared with donors-singletons. The aorta had greater stiffness and lower distensibility in donors compared with recipients; the differences for arterial indices were statistically more significant with donors-singletons.