Clinical management of twin reversed arterial perfusion cases: insights into a complex and challenging twinning.

Twin reversed arterial perfusion (TRAP) sequence occurs in approximately 1% of monozygotic pregnancies. The proposed pathogenesis is the association of paired artery-to-artery and vein-to-vein anastomoses through the placenta combined with delayed cardiac function of one of the embryos early in pregnancy. Presently the most commonly used technique for TRAP sequence is intrauterine radiofrequency ablation (RFA) of the cord of the recipient twin. This report shares the authors' experience in managing similar cases, the rationale leading to clinical decisions, the timing of the RFA procedure, the potential complications associated with TRAP, and the out-come of these two cases.