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. 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 weeks gestational age; birthweights of donors-recipients were comparable (donors: 1358±421g vs recipients: 1617±460g, P=0.2). Significant inter-twin differences were noted for cardiac function parameters. Recipients had greater septal thickness (donors: 2.3±0.15 vs recipients: 2.7±0.36mm, P=0.01) and globularity (lower sphericity index [donors: 1.76±0.1 vs recipients: 1.62±0.12, P=0.009]). They also had lower cardiac function (tricuspid annular plane systolic excursion [donors: 4.6±0.5 vs recipients: 4.1±0.4mm, P=0.02) and right ventricular fractional area change [donors: 30±1 vs recipients: 27.7±1.3%, P=0.0001]). Comparing 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, P=0.008] and lower pulsatile diameter [donors: 51±5 vs recipients: 63±10 µm, P<0.0001). Comparing with singletons, the differences were statistically more significant for donors. Evaluation in the neonatal period noted that cardiac function and arterial distensibility is affected in TTTS twins. These cohorts will benefit from close postnatal follow up for resolution of cardiac and arterial impairments.