Fetoscopic procedures and expectant management in complications of monochorionic twin pregnancies.

Monochorionic twin pregnancies are at significantly higher risks of pregnancy complications when compared to dichorionic twin pregnancies or singleton pregnancies. Some complications are specific to monochorionic twins, including twin-to-twin transfusion syndrome (TTTS, classified according to Quintero stages 1-5), selective fetal growth restriction (types 1, 2 or 3 according to the umbilical artery Doppler studies in the growth-restricted twin), twin anaemia-polycytaemia sequence (TAPS), or twin reverse arterial perfusuion sequence (TRAP). While fetoscopic laser ablation of the communicating blood vessels has been shown to improve pregnancy outcomes in TS stage 3 and above, it is unclear if fetoscopic treatment improves outcomes in selective fetal growth restriction, in TAPS and TRAP sequence. In some cases where the benefit of this procedure are unclear or performing the procedure is technically challenging, expectant management or other interventions (such as amniodrainage in TTTS, selective termination of pregnancy in type 2 selective fetal growth restriction and TRAP, or delivery if at a viable gestational age) are preferred. The Fetal Diagnostic Unit team at Monash Health is part of the statewide Victorian Fetal Therapy Service, and all such procedures are performed at Monash Medical Centre. In this study, we plan to audit the management and the outcomes of all monochorionic twin pregnancies with the above-mentioned complications, to investigate the best indications and timing of intervention. This project may be divided into smaller (BMedSc) projects, such as: - Evaluation of the management (type and gestational age) and outcomes of type 2 selective fetal growth restriction. - Evaluation of the management (type and gestational age) and outcomes of TRAP. - Analysis of the management (type and gestational age) and outcomes of TTTS by stage.