When the endometrium that grows in the uterine cavity grows in other parts of the uterine cavity than the mucous membrane that covers it, it is called endometriosis (endometriosis). The endometrium is often located in the pelvic peritoneum, ovaries, uterosacral ligament, and caesarean section scar, and is mainly seen in women of childbearing age. In recent years, its prevalence is increasing and it has become a common gynecological condition. 40% of patients have varying degrees of infertility and 50% have dysmenorrhea and lower abdominal pain, or they may not have any clinical manifestations. And about 30% of the infertility patients are caused by endometriosis. It seriously affects the health and quality of life of young and middle-aged women. In addition, recurrent miscarriages often occur in patients with endometriosis. Endometriosis affects infertility in several ways, affecting ovulation and corpus luteum function; causing pelvic adhesions, distortion and obstruction of the fallopian tubes; having toxic effects on spermatozoa and embryos; and altering the immune function of the body and the environment of the uterine cavity, which is not conducive to the implantation of pregnant eggs. A woman of childbearing age with a history of progressive dysmenorrhea or/and infertility and a painful hard nodule in the pelvis or an inactive cystic mass next to the uterus during gynecological examination can be initially diagnosed with endometriosis. Ultrasound and MRI are available for the examination of patients with endometriotic cysts (see Figures A and B below). Serum CA125 and CA199 are often mildly elevated in patients with endometriosis. The principle of treatment for endometriosis combined with infertility is early diagnosis and early treatment, and laparoscopy is the gold standard for the diagnosis of pelvic endometriosis. It is generally accepted that laparoscopic surgery should be performed first for primary, larger than 4 cm ovarian ectopic cysts (also known as chocolate cysts, or coeliac cysts) to reduce the risk of infection and improve the conditions for egg retrieval, followed by assisted conception treatment. However, surgery is also a double-edged sword. Ovarian coeliac debridement surgery can have an impact on the ovarian reserve function, reducing the number of sinus follicles in the ovary to some extent and decreasing the patient’s ability to conceive. This is caused by the fact that coeliacs are different from other common ovarian cysts (e.g. teratomas) in that they are more heavily adherent to the surrounding tissues. Also, the postoperative recurrence rate of endochondriasis is high, about 10% per year. Therefore, young and mildly ill patients are advised to prepare for pregnancy as soon as possible after surgery, either by having intercourse every three days or by ultrasound monitoring of ovulation to guide the timing of intercourse. If pregnancy does not occur after 6-12 months of trying, it is recommended to seek help from a fertility doctor. In the case of young women who do not intend to conceive, long-term use of contraceptive pills is recommended to delay recurrence if there are no contraindications. Women older than 35 years of age, or patients with severe disease, are advised to consult a fertility doctor directly to decide which fertility assistance technique to use to improve pregnancy rates, depending on the male partner’s semen status and the female partner’s fallopian tube. For example, intrauterine insemination (IUI) or in vitro fertilization-embryo transfer (IVF-ET), commonly known as “in vitro fertilization”. IUI is a method of artificially injecting optimally processed sperm into a woman’s uterus as an alternative to sexual intercourse to conceive a woman, with a success rate of about 10-15%. “In vitro fertilization”. The process involves the woman first using drugs to promote ovulation, removing the eggs from the woman’s ovaries, and the man removing the sperm, culturing the eggs and sperm together in the laboratory to become fertilized eggs and develop into embryos, and finally transferring the embryos into the uterine cavity, with a success rate of about 40-50%. Six months ago, she underwent laparoscopic left ovarian coelecystectomy and pelvic adhesion release for left ovarian coelecystectomy and adhesions. Six months after the operation, she was still infertile without contraception and came to us in the clinic with a strong demand for fertility. After discussion, we decided to allow her to be inseminated first. Li was very cooperative, but after two cycles, she was still infertile. We then decided to give her IVF treatment. She had a successful ovulation, egg retrieval and embryo transfer, and the ultrasound showed a single live intrauterine fetus one month after the procedure. For patients who have recurrence of coeliac disease after ovarian coeliac surgery, IVF is recommended as the first choice for treatment, which has a higher success rate than repeated surgeries.