I. What is uterine infertility? Uterine infertility is one of the leading causes of infertility. Both congenital and acquired pathologies of the uterus may affect embryo implantation, leading to infertility. Second, what are the causes of uterine infertility? Uterine infertility factors include congenital and acquired, as follows: 1. Congenital abnormalities of uterine development a. Congenital absence of uterus: often combined with absence of vagina, but usually normal ovarian development; b. Beginning uterus: also known as a trace uterus, the uterus is extremely small, only 1-75px, no uterine cavity, and is often combined with absence of vagina; c. Uterine dysplasia: also known as a naïve uterus, the uterus is smaller than normal, and there may be no menstruation or menstrual The uterus is smaller than normal and may not have menstruation or low menstruation; it is infertile after marriage. d. Bicornuate uterus or saddle uterus: mostly due to incomplete fusion of the uterine fundus during uterine development, the dysplastic and narrow bicornuate uterus may be prone to fetal position abnormality, mid-gestation miscarriage, and preterm delivery in late gestation. e. Septicidal uterus: classified into complete septate uterus and incomplete septate uterus, it is prone to infertility, miscarriage, preterm delivery, and abnormal fetal position. 2. Acquired uterine developmental abnormalities a. Chronic endometritis It is a pathological change of chronic pelvic inflammatory disease, which can cause infertility or miscarriage. The etiology may be reproductive tract infection after a history of uterine surgical operation, or hidden infection of the reproductive tract. b. Abnormal endometrial hyperplasia Abnormal endometrial hyperplasia is associated with long-term estrogen stimulation without progesterone counteracting it, leading to overgrowth of the endometrium, which affects the fertilization of the egg. c. Endometrial tuberculosis Endometrial tuberculosis is often secondary to tuberculosis of the lungs, intestines, mesentery, peritoneum and other organs, and the most common symptoms are infertility (55%), scanty menstruation and even amenorrhea. Tuberculosis of the endometrium destroys the environment in which the fertilized egg is deposited and develops, thus leading to infertility. d. Endometrial polyps Endometrial polyps are caused by focal overgrowth of the endometrium, and the incidence of infertility is as high as 15.6% to 32%. The causes of infertility due to endometrial polyps include interference with sperm and embryo transportation, alteration of endometrial development during the secretory phase, and decreased endometrial tolerance. Hysteroscopy is now the gold standard for diagnosing endometrial polyps. Hysteroscopy can provide direct vision and biopsy the lesion to improve the accuracy and precision of diagnosis. e. Uterine fibroids Uterine fibroids are divided into subplasma fibroids, interstitial fibroids, and submucous fibroids according to different parts of the uterus. Subplasma fibroids have no significant effect on fertility outcome; intermural fibroids can reduce the conception rate and increase the miscarriage rate, and intermural myomectomy cannot significantly increase the clinical pregnancy and live birth rate of patients; patients with submucosal fibroids are often associated with excessive menstruation, bleeding between menstrual periods, infertility, or miscarriage, which is caused by the twisting and deformation of the uterine cavity due to the submucosal fibroids, which significantly reduces the implantation rate and pregnancy rate. Hysteroscopy is the gold standard for the diagnosis of submucosal fibroids and the treatment of choice. f. Uterine adhesion: It refers to the adhesion of the uterine cavity caused by endometrial damage due to various reasons. Its clinical manifestations are menorrhagia, amenorrhea, recurrent miscarriages and infertility, etc. Even if conception is successful, preterm delivery or combined with abnormal placenta position, such as placenta praevia or placental implantation, may occur. Hysteroscopy is the gold standard for the diagnosis of uterine adhesions and hysteroscopic adhesion release is the standard procedure for the treatment of uterine adhesions. Hysteroscopy allows direct visualization of the site and extent of the adhesions and the type of adhesions. The type of uterine adhesions and the degree of uterine atresia correlate with the reproductive outcome of treatment. Treatment of uterine adhesions includes complete and accurate separation of adhesions and prevention of reattachment after separation as well as promotion of repair of damaged endometrium. In patients with severe uterine adhesions, the prognosis is often poor. g. Cervical insufficiency Cervical insufficiency can be caused by congenital cervical dysplasia, or due to abortion, induced abortion or cervical conical resection. Treatments for cervical insufficiency include: transvaginal cervical cerclage, laparoscopic uterine isthmus cerclage Normal uterus is a prerequisite for fertility. Both congenital and acquired uterine abnormalities can lead to infertility. With the birth of the world’s first “transplanted uterus” baby and the first successful uterus transplant in China, uterus transplantation has made it possible for patients with absolute uterine infertility (congenital absence of a uterus, post hysterectomy, non-functioning uterus, etc.) to have their own children.