Female fertility is affected by many factors, such as ovarian function, fallopian tube patency, uterine environment, and mental state, among which the ovaries and endometrium are more important. In reproductive medicine, ovarian dysfunction, poor ovarian reaction, intrauterine adhesion, recurrent implantation failure, and thin endometrium are the five most common diseases that affect fertility. These five diseases lack effective treatment, and previous studies have shown that platelet-rich plasma is promising in treating these five diseases, so it is necessary to further explore the therapeutic effect and potential mechanism.

Inclusion Criteria:

• Premature ovarian insufficiency: ① Women aged >18 and <40 years old; ② Oligomenorrhea or amenorrhea for more than 4 months (excluding pregnancy); ③ Basal follicle stimulating hormone (FSH) >25IU/L (interval >4 weeks) at least 2 times, or total antral follicles (AFC) <5, or anti-Mullerian hormone (AMH) <1.1ng/mL.
• Poor ovarian response: ① Advanced age (≥40 years) or other risk factors for poor ovarian response; ② Poor ovarian response in previous IVF cycle, with ≤3 oocytes retrieved using conventional protocols; ③ Decreased ovarian reserve (antral follicle count <5~7 or anti-Müllerian hormone <0.5~1.1 ug/L). Meeting any 2 of the above 3 criteria is sufficient.
• Intrauterine adhesion: ① Diagnosed by hysteroscopy and scored ≥5 points according to the American Fertility Society criteria (1988); ② With symptoms such as reduced menstrual flow amenorrhea, periodic lower abdominal pain, infertility, or recurrent miscarriage; ③ Adult women with the desire to conceive.
• Thin endometium: ①Endometrial thickness <7mm on ovulation day or on the day of human chorionic gonadotropin (HCG) injection, or <7mm on progesterone conversion day when using conventional hormone replacement therapy, ②adult women with the desire to comceive.
• Repeated implantation failure: Women under 40 years old who have failed to achieve clinical pregnancy after transplanting at least three high-quality embryos within three fresh or frozen cycles. High-quality embryos include: Day 3 embryos (with ≥8 cells, evenly sized blastomeres, and <10% fragmentation) and blastocysts (≥3BB).

Exclusion Criteria:

• Alanine aminotransferase > 3 times the normal upper limit or estimated glomerular filtration rate (EGFR) < 90 ml/min;
• Suffering from hemorrhagic diseases (such as hemophilia) or taking anticoagulant or antiplatelet drugs;
• Suffering from serious mental illness, cardiovascular and cerebrovascular diseases and malignant tumors;
• Suffering from diabetes with poor blood sugar control or other systemic diseases;
• Drug abuse, alcoholism or drug addiction;
• Participated in other interventional clinical studies within half a year;
• Poor compliance;
• Other circumstances that are not suitable for participating in the study.