Effect of Reproductive Tract Microbiota on Pregnancy Outcome in IVF/ICSI

Inclusion Criteria: 1. The sampling cycle of all samples requires no use of glucocorticoids, antibiotics and vaginal drugs within the cycle of this month; No cervical treatment within a week; No irrigation, asexual life within 5 days; Strict contraception in this month; 2. Male infertility (Related tests were normal, because the male factor alone required the first IVF/ICSI cycle; Follow-up of included patients was conducted to determine whether embryo transplantation was performed, and the score of transferred embryos was recorded, and the final control group would be confirmed after achieving clinical pregnancy) OR Recurrent implantation failure (Previous ≥3 consecutive embryo transfer failures) OR Recurrent spontaneous abortion (≥2 consecutive spontaneous abortions or embryo damage) Exclusion Criteria: 1. Acute genital tract inflammation (including vagina, cervix, endometrium and pelvic cavity) 2. Previous diagnosis of intrauterine adhesion or mechanical damage to the endometrium; drugs and surgery can not restore the function (endometrium thickness \<7mm in the window period before transplantation) 3. Untreated hydrosalpinx, submucosal or \>4cm intramuscular uterine fibroids, adenomyosis, stage III-IV endometriosis confirmed by surgery, endometritis diagnosed by pathology and other definite factors might affect implantation 4. Chromosomal abnormalities in couples may lead to miscarriage, fetal malformation and other diseases 5. Previous examination indicated the existence of DOR (FSH≥9U/L and/or AMH ≤1.1ng/ml and/or AFC≤5-7) 6. Those with polycystic ovary syndrome, high prolactinemia and other ovulation disorders 7. Those with congenital adrenal hyperplasia, hypothyroidism/hyperthyroidism, diabetes, metabolic syndrome and other endocrine and metabolic diseases 8. BMI less than 18 or more than 25 9. Previous autoimmune diseases such as anti-heart coagulation syndrome, sjogren's syndrome and rheumatoid arthritis 10. Prethrombotic hypercoagulability or family history of thrombosis 11. Female genital tract deformities (whether or not surgically corrected) 12. Those within the programme of oocyte or sperm donor 13. Those with previous history of various types of cancer or serious systemic diseases (such as heart, lung and blood diseases) or mental diseases