First trimester intervention in twin reversed arterial perfusion (TRAP) sequence – does size matter?

Objective: To evaluate the outcome of first trimester intervention (12+0 to 13+6 weeks of gestation) in pregnancies complicated by TRAP sequence. Methods: From 2010 onwards, all patients diagnosed with monochorionic diamniotic TRAP sequence undergoing intrafetal laser ablation (IFL) prior to 14+0 weeks of gestation at the University of Bonn were retrospectively analysed for intrauterine course and pregnancy outcome. Results: In the study period twelve patients were treated by IFL. The mean gestational age at intervention was 13.1 ± 0.5 weeks (range 12+4 – 13+6). In all cases one intervention sufficed to disrupt…