Study on Initiation and Immunological Mechanism of Childbirth

This study is a prospective observational study. The participants including 40 pregnant women who have been filed and delivered in our hospital will enrolled, collect venous blood will be collected at different stages of pregnancy, delivery, postpartum to detect the concentration of fetal free DNA, the frequency of associated immune cells, and the expression of functional molecules, so as to explore the immunological mechanism of delivery initiation.

Inclusion Criteria:20 normal parturients and 20 pregnant women with threatened preterm labor who had undergone antenatal examination and delivery in Beijing Ditan Hospital were fully informed of the risks and volunteered to join the study and signed the informed consent form.Exclusion Criteria:1. Combined with HCV, HIV, syphilis or other infectious diseases.2. Chronic diseases such as diabetes, hypertension, thyroid disease and autoimmune disease.3. Both husband and wife or their families have delivered congenital abnormal fetus in the past.4. Either spouse is unwilling to participate in this study.