Abstract: Objective: Detect thyroid level of twin pregnancies, to analyze the relationship between pregnancy complications and thyroid level. Methods: Select 136 women with twin pregnancies who were enrolled in Obstetrics and Gynecology Hospital Affiliated to Nanjing Medical University from June 2016 to January 2017. These pregnant women were classified into two groups: one with complicated pregnancy (92 cases), the other with uncomplicated pregnancy (44 cases). The control group consisted of 50 normally single pregnant women. Compare thyroid stimulating hormone (TSH) and serum free thyroxine (FT4) between these three groups. Calculate the cut-off value of TSH in predicting complications of twin pregnancy with the ROC (receiver operating characteristics) curve. Results: TSH level in group of twin pregnancy women with complications was obviously high compared with the other groups, the difference was statistically significant (P＜0.05); There was no statistical difference between TSH level in uncomplicated group and that in normally single pregnancy group(P＞0.05). There were no statistical differences between FT4 in these three groups(P＞0.05). When the cut-off value of TSH was 5.18 mIU/L，the susceptibility and specificity was 63% and 91% respectively. Conclusions: TSH level increased in twin pregnancy women with complications. To detect TSH level has a high value of predicting the complications in twin pregnancy women.

Key words: Twins, Pregnancy complications; , Thyrotropin, ROC curve