Common causes of infertility: (1) Female factors: (1) Fallopian tube factors: inflammation, adhesions, obstruction, hydrocele, etc. (2) Ovulation disorders: endocrine disorders, ovarian lesions, pituitary disorders, hypothalamic injury, abnormal thyroid or adrenal axis function. (3) Cervical and uterine factors: inflammation, abnormal mucus function, abnormal immunological function of the cervix, uterine adhesions, endometrial polyps, uterine fibroids, etc. (4) Vulvovaginal factors: abnormal development or acquired mechanical injury causing scar stenosis, vaginitis, etc. (2) Male factors: (1) Sperm production disorders: varicocele, orchitis, reproductive tract infection, cryptorchidism, testicular hypoplasia, physical and chemical factors such as carcinogenesis, chemotherapy, alcoholism, etc. causing sperm reduction or azoospermia. (2) Sperm transport disorders: vas deferens obstruction, absence, sperm vesicle absence, etc., impotence, retrograde ejaculation, non-ejaculation. (3) Sperm abnormalities: abnormal acrosome reaction. (3) Immunological factors: the presence of anti-sperm antibodies. (4) Spiritual and psychological factors of both parties: eagerly anticipating pregnancy. (5) Unknown causes. Treatment: 1. Fallopian tube factors: lavage or reconstructive surgery. 2. Ovulation disorders: Clomiphene ovulation promotion, HMG, FSH, bromocriptine, GnRH, etc. 3. Uterus, cervix, vulvovaginal factors: different surgeries or drugs for the lesions. 4, immune factors: avoid antigenic stimulation and immunosuppressive treatment, artificial insemination. 5, male factors: less weak sperm can be drugs or surgery, ineffective to perform assisted reproduction techniques, azoospermia testicular biopsy has sperm feasible assisted reproduction. Common assisted reproduction techniques: 1, artificial insemination: the main indications: 1, the male partner less weak sperm, liquefaction abnormalities, sexual dysfunction, genital abnormalities; 2, cervical factors; 3, reproductive tract abnormalities and psychological factors leading to sexual intercourse can not; 4, immune infertility; 5, unexplained infertility. 2. IVF: Main indications: 1. gamete transport disorders due to various factors in the female; 2. ovulation disorders; 3. endometriosis; 4. oligozoospermia in the male; 5. unexplained infertility; 6. immune infertility.