Monochorionic Diamniotic Twin Pregnancy; a Retrospective Study on Twintwin Transfusion Syndrome and Related Disorders.

OBJECTIVE We assessed the clinical characteristics and perinatal outcome of disorders specific to monochorionic diamniotic (MD) twin pregnancies, focusing on twin-twin transfusion syndrome (TTTS) and related disorders, such as selective intrauterine growth restriction (sIUGR), inter-twin amniotic fluid discordance (AFD), and twin anemia polycythemia sequence (TAPS). METHODS We retrospectively reviewed 69 cases of MD twin pregnancies delivered after 22 weeks at our institution from January 2009 to September 2013. RESULTS TTTS occurred in 9 cases (13%). There was a total of 11 cases (16%) of MD twins with sIUGR in this period. One case developed TTTS. All 3 cases (4%) of AFD in this study developed TTTS or sIUGR. CONCLUSION AFD should be recognized as predictors of TTTS or sIUGR. Further studies on TTTS-related disorders allow a more precise subgroup categorization that enables optimal management.