Abstract: Objective To investigate risk factors and the changes of coagulation function in early pregnancy patients with missed abortion. Methods The retrospective study was performed. A total of 349 patients diagnosed with missed abortion in early pregnancy in Maternal and Child Health Hospital Affiliated to Anhui Medical University between March 2018 and September 2018 were selected as observation group. 153 normal pregnancy women who had artificial abortion due to unplanned pregnancy at the same period were selected as control group. The characteristics of general information, blood routine and coagulation tests of the two groups were analyzed. Logistic regression analysis was used to identify risk factors. Results ①Age in observation group was older than that in control group（29.68±4.72 vs 27.64±5.38, P<0.001）. The number of spontaneous abortions was also higher than that in control group（0.19±0.53 vs 0.06±0.29, P=0.001）. ② The level of D-dimer was higher, and fibrinogen degradation product（FDP）and fibrinogen were lower in observation group compared to those in control group. In observation group, D-dimer level in recurrence group was higher than that in newly diagnosed group. Prothrombin time（PT）, activated partial thromboplastin time (APTT) and thrombin time (TT) in observation group were higher than that in control group（P<0.01）. There was no significant difference in platelet count between the two groups（P>0.05）. ③Logistic regression analysis showed that age and history of spontaneous abortion were risk factors for missed abortion: Age≥25~30 years old (odds ratio（OR）5.690; 95% CI 3.184~10.168), age ≥30 years（OR 9.882; 95% CI 4.949~19.731）, history of spontaneous abortion（OR4.994; 95% CI 1.881~13.257）. Conclusion Although patients with missed abortion during early pregnancy showed hyperfibrinolysis, most patients had no obvious coagulation abnormality. Age and a history of spontaneous abortion were the risk factors for missed abortion. For women aged older than 25 years or with a history of spontaneous abortion in early pregnancy, coagulation tests might help reduce their incidence of missed abortion by appropriate interventions.

Key words: Missed abortion, Coagulation, Early pregnancy