For young couples, it is generally considered logical to have a smooth delivery in October, however, the incidence of infertility in China is about 10%, and it is increasing year by year. There are many reasons for infertility, and one of the important reasons is endometriosis. What is endometriosis? Endometriosis, as the name implies, is the growth of the endometrium in a location other than the normal site; the strict medical definition is the presence of endometrial tissue (glands and mesenchyme) with a growth function in a location other than the covered endometrium and myometrium of the uterine cavity. The most common site is the ovaries, in addition to the peritoneum, the uterosacral ligament, the cervix, and the cesarean scar. It is one of the most common diseases in women of childbearing age. In recent years, the incidence of endometriosis has tended to increase and it has become a disease that has been much studied by gynecologists but remains confusing due to the presence of the following characteristics It is a benign disease with the usual malignant behavior of malignant tumors such as infiltration, proliferation, spread, and metastasis; treatment is not directed at the cause because the pathogenesis is not clear, and therefore incomplete; symptoms and signs do not completely match, and the lesions are widespread, diverse, invasive, and recurrent, making it a difficult disease to treat. Patients with endometriosis are often plagued by severe dysmenorrhea, chronic abdominal pain, menstrual abnormalities, and infertility. The rate of combined infertility is as high as 40%, and among infertile patients, the rate of combined endometriosis can be as high as 80%. The causes of infertility due to endometriosis are multi-linked. Normal conception is an incomparably delicate process that begins with a developed egg being detected by the umbrella of the fallopian tube after ovulation, transported and lodged in the abdomen of the fallopian tube where it meets the sperm and becomes a fertilized egg, which is then transported by the fallopian tube to the uterine cavity where it is planted in the endometrium (implanted). An abnormality in any one of these parts can lead to infertility. First, patients with endometriosis often have abnormal ovarian function. 17% to 27% of patients have ovulation disorders, possibly related to elevated prostaglandins in the peritoneal fluid; sometimes, even when ovulation occurs, luteal insufficiency occurs to affect conception. In some cases, even if ovulation occurs, luteal insufficiency may affect conception. In another 18% to 79% of patients, luteinization of the unruptured follicle occurs, which means that the follicle is mature enough to ovulate, but eventually the follicle does not ovulate. The progesterone secreted by the luteinized follicles is similar to that of normal ovulation, so the basal body temperature test and ovulation test are the same as normal ovulation. This is one of the causes of infertility. Secondly, the function of the fallopian tubes to transport eggs is decreased. Ectopic endometrium can grow in the ovaries or fallopian tubes, causing extensive adhesions around them, resulting in obstruction, twisting, or blockage of the fallopian tubes. Poorly functioning fallopian tubes cannot transport sperm to the intended site to meet the egg. Furthermore, the effect on fertilization: ectopic endometrium grows in the pelvic and abdominal cavity. In patients with endo, especially those with dysmenorrhea, the microenvironment of the abdominal cavity is altered and a large number of cytokines are present, endangering sperm and fertilized eggs. Next, the effect on fertilization: Studies have found that endometriosis patients have abnormalities in the endometrium itself, as well as changes in the intrauterine environment that can affect the fertilization of the egg. Finally, the rate of spontaneous abortion after pregnancy in patients with endometriosis is as high as 40%, compared to 15% in normal women. This shows the importance of proper treatment of endometriosis in young women who want to have children, and the need to promote pregnancy after treatment. The process of pregnancy and postpartum breastfeeding is also beneficial in treating endometriosis and reducing and delaying its recurrence. So, how should endometriosis be treated? What can be done to promote pregnancy in patients with combined infertility? Since this is an estrogen-dependent disease, the main source of estrogen is the ovaries. To date, there is no ideal cure other than radical surgical treatment (removal of the ovaries). For patients who require fertility, individualized conservative treatment is more necessary. Currently, laparoscopic confirmation of diagnosis and surgery plus medications are considered the gold standard for the treatment of ectopic disease. After the diagnosis of mild cases, some drugs are often used to temporarily suppress ovarian function, such as pseudopregnancy therapy and pseudomenopause therapy, to achieve atrophy, degeneration and necrosis of the ectopic endometrium. The author once treated a patient with mild dysmenorrhea who was still infertile after two years of herbal medicine, immunotherapy, and ovulation treatment in a foreign hospital. “In addition to intraoperative electrocoagulation, the drug GnRH-a was recommended for a short period of time after surgery, and after resumption of menstruation, ovulation treatment was given. In moderately severe cases, the lesions often involve the ovaries and can lead to pelvic adhesions. The aim of surgery in this case is to remove the cyst, remove the visible lesions, separate the adhesions and restore the normal anatomy of the fallopian tubes and ovaries as much as possible. During the surgery, great attention must be paid to the protection of ovarian function. The follicles are the basis of life, and many studies have shown that endometriosis itself damages ovarian function, reducing the ovarian reserve, which means that fewer follicles can develop and mature. This requires the surgeon to “take care” of the remaining normal ovarian tissue during surgery and to preserve it as much as possible. After the surgery, depending on the severity of the disease, it is determined whether the patient should try to conceive directly or use medication followed by pregnancy promotion techniques such as IVF and IUI. Therefore, in patients with endometriosis, the goal of treatment is to remove the lesion, relieve pain, promote conception, and prevent recurrence. Younger patients should actively promote pregnancy, which generally has the highest probability of pregnancy within 1 year after surgery, and should actively use this period to give proper guidance to patients with endometriosis.