Obstetric and perinatal outcomes from The Australian and New Zealand Twin-Twin Transfusion Syndrome Registry

OBJECTIVE: Our purpose was to investigate the antepartum characteristics an d perinatal outcomes of twin-twin transfusion syndrome cases from a multice nter national registry. STUDY DESIGN: Perinatal centers in Australia and New Zealand voluntarily no tified a central evaluation registry with information on identified pregnan cies with twin-twin transfusion syndrome during 1995 through 1998. RESULTS: One hundred twelve cases of twin-twin transfusion syndrome were re gistered. The median gestation at diagnosis was 21.5 weeks (range, 14.4-34. 6 weeks). Oligohydramnios-polyhydramnios sequence was the most common prese ntation, with 84% of cases involving "stuck" twinning. Therapeutic amniored uction was used in 92 cases (82.1%), with the median number of procedures p er case being 2 (range, 1-23). The median gestation at delivery was 29 week s (range, 18-38 weeks). The overall perinatal survival rate was 62.5%. Abno rmal findings on cranial ultrasonography were present in 27.3% of live neon ates, and periventricular leukomalacia was reported in 10.8%. Increased ges tational age at delivery, the presence of umbilical artery diastolic flow, and a prolonged interval from final amnioreduction to delivery were positiv ely associated with the delivery of live fetuses without complications. CONCLUSION: The majority of antenatally identified cases of twin-twin trans fusion syndrome are managed with serial amnioreduction. Despite contemporar y obstetric and neonatal management strategies, perinatal mortality and mor bidity rates are high.