Infertility is medically defined as one year without any contraception, with normal sexual intercourse and no successful pregnancy. Infertility is a common problem that affects approximately at least 10-15% of couples of reproductive age. I. Tubal infertility The fallopian tubes play an important role in female reproductive activity, not only as a channel for transporting sperm and eggs, but also as a place for early embryonic development. Fallopian tube incompetence or dysfunction becomes the main cause of female infertility. 1, tubal inflammation and pelvic inflammation: Infertility caused by tubal factors is most commonly seen due to genital inflammation, which is closely related to abortion, medication abortion, placement of intrauterine device, unclean abortion or delivery, unclean sex life, etc. Inflammation causes adhesions and obstruction of the fallopian tubes, which affects peristalsis and cilia movement, thus affecting the meeting and transport of sperm and eggs, resulting in infertility. Inflammation of the fallopian tubes is caused by upstream infection and can also be secondary to appendicitis or other pelvic and abdominal inflammatory conditions. The common causative organisms are staphylococcus, streptococcus, chlamydia, mycoplasma, gonococcus, etc. Tuberculosis of the fallopian tubes: Tuberculosis of the reproductive system accounts for about 10% of the causes of infertility and is very likely to cause obstruction of the fallopian tubes, which can also involve the ovaries, endometrium and cervix. Genital tuberculosis is often secondary, mostly from pulmonary tuberculosis, peritoneal tuberculosis through hematogenous or lymphatic transfer to the genitalia, mostly bilateral involvement. Tuberculosis of the fallopian tubes accounts for 85-95% of genital tuberculosis. The tubercle bacilli first infect the muscularis or submucosa and then progress to the mucosa and plasma layer. The infected fallopian tubes only show congestion and edema in the early stages, which are not easily detectable. The adhesion type presents with thickening of the fallopian tubes, thick and rigid, narrowing of the lumen, bead-like changes, caseous necrotic tissue, tight adhesions with surrounding tissues, destruction of cilia, and abnormal peristalsis. The exudative type is dominated by exudate, the abdominal cavity is widely scattered with corn-like nodules, the fallopian tubes are swollen and thickened, the mucous membrane of the fallopian tubes is severely damaged, and the amount of abdominal water can reach 500-800ml. 3. Endometriosis: The causes of infertility caused by endometriosis are many, and the effect on the fallopian tubes is one of them. The ectopic endometrium causes bleeding and adhesions, causing the fallopian tubes to adhere to the surrounding tissues. At the same time, the ectopic endometrium produces too much prostaglandin, which interferes with the rhythmic peristalsis of the fallopian tubes, resulting in abnormal peristalsis and obstruction of egg collection. 4, gonorrhea and mycoplasma, chlamydia infection: In recent years, the rate of mycoplasma and chlamydia infection has been increasing year by year. Gonorrhea, mycoplasma and chlamydia can be infected along the mucous membrane upstream, through the endocervical lining, endometrium, fallopian tube lining to the pelvic peritoneum, causing abnormal cervical mucus, damage to the epithelial cells of the fallopian tube mucosa, scarring in the fallopian tube, adhesions, adhesions and atresia around the fallopian tube umbrella, leading to infertility. 5. Others: post-fallopian tube sterilization, post-fallopian tube resection, congenital tubal dysplasia or abnormalities, tubal adhesions and inaccessibility after conservative treatment of ectopic pregnancy, tubal dysfunction (such as interstitial or isthmus spasm), etc. Normal ovulation in women is controlled by the hypothalamic-pituitary-ovarian axis. The hypothalamus secretes gonadotropin-releasing hormone (GnRH) in a pulsatile manner, which acts on the pituitary gland to stimulate the anterior pituitary gonadotrophs to secrete folliculopoietin (FSH) and luteinizing hormone (LH), which in turn act on the ovaries to play a regulatory role in follicle development, maturation, ovulation, luteal formation and ovarian steroid hormone secretion. In turn, ovarian secretion of hormones plays a feedback role to the higher level centers. Therefore, no matter which part of the hypothalamic-pituitary-ovarian axis has a problem, it can lead to ovulation disorder, which in turn leads to infertility. 1. Hypothalamic dysfunction: It mostly occurs in young women and is related to mental tension, work stress, sudden mental stimulation, excessive exercise and apprehension, in addition, many young women advocate dieting and weight loss, resulting in anorexia nervosa, as well as long-term use of contraceptives, which can cause changes in hypothalamic GnRH pulses, resulting in abnormal secretion of pituitary gonadotropins and causing ovulation disorders. Patients show no development of sexual characteristics after puberty, primary amenorrhea, a genetic disease, is dominated by low gonadotropins, sex hormones, accompanied by hyposmia or absence of smell. 2, pituitary dysfunction: various causes of low secretion of pituitary gonadotropins, resulting in ovulation disorders. For example, pituitary tumor, most commonly prolactin microadenoma, when the tumor compresses the anterior pituitary gland, resulting in disorder of anterior pituitary hormone secretion. Empty saddle syndrome is a congenital transverse septal defect of the pterygoid saddle, with cerebrospinal fluid flowing into the saddle to compress the anterior pituitary lobe. Silhan’s syndrome occurs secondary to massive blood loss, ischemic necrosis of the pituitary gland, and loss of the ability to synthesize gonadotropins. The most common clinical condition is idiopathic hyperprolactinemia, in which excessive PRL feedback inhibits hypothalamic secretion of GnRH and attenuates or blocks the ovarian response to GnRH, preventing the formation of pre-ovulatory estrogen and LH peaks and inhibiting FSH-induced estrogen production and LH-induced progesterone production. Increased TRH secretion in primary hypothyroidism is accompanied by increased PRL. In addition, any drugs that interfere with dopamine anabolic reabsorption and block dopamine binding to receptors can increase PRL, which in turn affects ovulation and leads to infertility. 3. Ovarian dysfunction: The hypothalamus and pituitary gland secrete gonadotropin-releasing hormone and gonadotropin normally, but the ovaries react to gonadotropin to synthesize sex hormones, resulting in anovulation. The most common clinical manifestations of polycystic ovary syndrome (PCOS) are amenorrhea or scanty menstruation, hyperandrogenemia or hyperandrogenic manifestations such as hirsutism, acne, obesity, and 10 follicles in one section of the ovary with no dominant follicle on ultrasound. In recent years, there has been an increase in the number of people with premature ovarian failure (POF) and ovarian insensitivity syndrome (ROS), which are characterized by persistent amenorrhea, infertility, and perimenopausal symptoms caused by some cause before the age of 40 in women with normal age of menarche or delayed puberty and normal development of secondary sexual characteristics, accompanied by decreased estrogen and elevated FSH and LH, the former with atrophied ovaries and basically no follicles In the former, the ovaries are atrophied with essentially no follicles, whereas in the latter, the ovaries are normal in appearance with multiple primordial follicles and primary follicles. Some mild ovarian ovulation disorders such as follicular dysplasia, luteal insufficiency, and luteinized unruptured follicle syndrome (LUFS) are also causes of infertility. Follicular dysplasia is a condition in which the follicle diameter is significantly smaller than that of a normal follicle, with poor tone and slow growth, and development stops when it reaches a certain level. Luteal insufficiency refers to insufficient secretion of estrogen and progesterone by the corpus luteum and inadequate secretory changes in the endometrium, resulting in luteal bleeding and obstruction to the implantation of pregnant eggs. Ovarian inflammation and ovarian tumors can also cause ovarian ovulation dysfunction. In addition, some chromosomal abnormalities, such as Turner syndrome and simple gonadal insufficiency, usually have primary amenorrhea and infertility as the main symptoms. Immunological infertility refers to the presence of anti-fertility immune evidence when all the indicators of infertility tests are normal for both partners. The most frequent one is anti-sperm immunity. When the female reproductive tract is inflamed or damaged, sperm antigens enter the female reproductive tract and local and systemic immune reactions occur, interfering with sperm capacitation and acrosome reactions, and also affecting sperm penetration of the zona pellucida, causing infertility. studies in the 1950s showed that the occurrence of anovulation was associated with anti-ovarian antibodies, an increase in atretic follicles and a decrease in growing and mature follicles in the ovary. In addition, some cases have the production of anti-hyaloid antibodies, which prevent sperm from binding to the zona pellucida; anti-endometrial antibodies cause damage to the biochemical metabolism and physiological function of endometrial tissue cells, which affects fertilized egg implantation and embryo sac development. Other causes of infertility Cervical infertility is mainly divided into two parts. On the one hand, there are abnormalities in the physiological anatomy and position of the cervix, such as congenital atresia or stenosis of the cervix, adhesions or stenosis of the cervix caused by uterine cavity operations or infections, etc., and sperm cannot easily enter the cervical canal due to excessive curvature of the uterus. On the other hand, there are abnormalities of cervical mucus, such as low secretion or abnormal nature of cervical mucus during ovulation, which include increased phagocytosis and inflammatory cells in the secretion caused by acute and chronic inflammation of the cervix, large number of phagocytosis and sperm killing; abnormal PH value and glucose content of cervical mucus caused by mycoplasma and chlamydia infections; changes in the nature of cervical mucus after the application of clomiphene and other drugs; positive anti-sperm antibodies to cervical mucus etc. Clinically, there are still some patients who cannot conceive despite normal follicular development, normal ovulation, no significant abnormalities in hormone levels, patent fallopian tubes, no abnormalities in antibody and chromosome tests, and normal semen of the lover after various tests. This kind of unexplained infertility does not exceed 5% of infertility patients. Some studies have shown that the causes of infertility in this group may be related to mental factors, environmental factors, mood, stress, etc. Attempts can be made to help conception through psychological counseling, conception counseling and assisted reproduction techniques.