Recent years, women with infertility have become more and more and thus assisted reproductive technology has been applied in a broad range. And the quantities of twin pregnancies are larger and larger. However, complicated twin pregnancy subsequently increased including selective intrauterine growth restriction (sIUGR), twin growth discordance, twin transfusion syndrome (TTTS) and intrauterine fetal death (IUFD). The occurrence of complicated twin pregnancy has been the leading cause of morbidity and mortality in twin and mother. Meanwhile, twin pregnancy, especially monochorionic type has suffered from higher rate of chromosomal anomalies and structural anomalies. Therefore, it is important that more attention should be paid to the prediction, clinical evaluation and the occurrence of chromosomal anomalies and structural anomalies in complicated twin pregnancy.