1. Female factors: 1. Ovulation monitoring: basal body temperature (BBT), vaginal exfoliative cell smear, cervical mucus examination, ultrasound to monitor follicle development and ovulation, sex hormone measurement. 2. Luteal function examination: luteal peak hormone measurement, endometrial biopsy. 3, tubal patency examination: tubal lavage, hysterosalpingography, ultrasound pelvic imaging, hysteroscopic lavage, combined hysterolaparoscopy. 4. Uterine factors: ultrasound, hysteroscopy. 5. Endometriosis: gynecological examination, ultrasound, CA125 measurement, laparoscopy. 6. Immunological factors: various antibody tests, post-coital tests. 2. Male factors: 1. Routine semen examination: to determine the presence or absence of oligospermia, weakness, teratozoospermia, azoospermia, poor liquefaction or non-liquefaction, and the presence or absence of retrograde ejaculation, etc. 2. Physical examination: testicular and epididymal development, presence of varicocele, absence of vas deferens, etc. 3. Sex hormone measurement: FSH, LH, T, PRL. 4. Epididymal/testicular aspiration/biopsy: further examination of azoospermia to determine whether IVF/ICSI can be performed. 5. Immunological factors: anti-sperm antibody test, sperm agglutination test. Treatment: I. Ovulation disorder: ovulation induction – Clomiphene, HMG, HCG, GnRHa, bromocriptine II. Luteal insufficiency: supplementation of luteal function, ovulation promotion III. Fallopian tube treatment: lavage, laparoscopic decomposition of tubal adhesions, ostomy, etc. IV. Uterine lesions: hysteroscopic removal of polyps, decomposition of adhesions, longitudinal resection, electrosurgery of submucosal myomas V. Endometriosis: GnRH-a, laparoscopic surgery, assisted reproductive technology (ART) VI. AIH) 2, in vitro fertilization – embryo transfer (IVF-ET) 3, intracytoplasmic single sperm microinjection (ICSI) 4, preimplantation genetic diagnosis (PGD) 5, assisted hatching (AH)