The purpose of this study is to initially explore the efficacy of adipose-derived stromal vascular fraction (AD-SVF) therapy in the treatment of refractory endometrial infertility.

Patients with refractory thin endometrium (endometrial thickness < 6 mm at late proliferative phase or after high-dose estrogen therapy) and/or moderate to severe intrauterine adhesion are recruited for fertility. After detailed explanation of the treatment plan, written informed consent will be obtained from the patients. The subjects undergo liposuction performed by plastic surgeons to obtain adipose tissue, from which AD-SVF is isolated and extracted for intrauterine infusion therapy. Six months post-AD-SVF treatment, the improvement in menstrual volume and endometrial thickness will be assessed during follow-up visits. The subjects will be advised, based on their personal inclination, to attempt conception (hysteroscopic surgery will be repeated if necessary), and their early pregnancy outcomes will be documented in subsequent follow-ups.

Inclusion Criteria:

1. refractory thin endometrium (endometrial thickness < 6 mm on the day of ovulation or the day of endometrial transformation during a hormone replacement cycle) and/or moderate to severe intrauterine adhesion；
2. Inability to undergo autologous bone marrow stem cells-scaffold (BMSC) transplantation due to failed bone marrow aspiration, or lack of significant effect following the BMSC treatment;
3. with fertility intentions;
4. normal ovarian function or availability of cryopreserved embryos;
5. 18kg/m^2 < body mass index (BMI) < 30kg/m^2;

Exclusion Criteria:

1. Chromosomal karyotype abnormalities in one spouse;
2. Severe endometriosis, uterine fibroids affecting the uterine cavity morphology, or uterine malformations;
3. Abnormalities in coagulation function, hepatic or renal function, or other underlying conditions deemed by the investigator to potentially impact the study's progression (uncontrolled hypertension, diabetes, autoimmune diseases, etc.);
4. Contraindications for pregnancy;
5. Contraindications for hormonal cycle therapy;
6. History of pelvic tumors;
7. Simultaneous participation in other clinical studies.