Xiao Li, 32 years old, has not been pregnant for 5 years after marriage. Xiao Li’s menstruation was regular and ovulation was normal according to the medical science book and the various ovulation test methods informed by the doctor. Xiao Li’s husband also went to the hospital for examination and his semen was normal. What bothered Xiao Li was that although no abnormalities were found in the various tests, she had been trying for 3 years during ovulation, but still no results. So what is the cause of the couple’s infertility? In fact, it is very common for infertile couples to have normal ovulation and normal semen. Research by scholars at home and abroad found that half of the causes of infertility in couples with normal ovulation and semen have endometriosis. Endometriosis is commonly known as a condition in which the endometrium grows outside the uterus in a physiological state. If it grows on the ovaries, it forms ovarian endometriosis (i.e., chocolate cysts); if it grows in the pelvis, it forms pelvic endometriosis; and the endometrium can also grow in other parts of the body. Collectively, these are called endometriosis. Endometriosis is one of the common gynecological diseases, with a prevalence of 10% in women of childbearing age and 30%-50% in infertility patients. Infertility due to endometriosis is known as endometriosis infertility. The main manifestations of endometriosis are chronic pain and infertility. Among the chronic pains are mainly progressive and worsening dysmenorrhea, chronic pelvic pain and deep intercourse pain. If you experience cramping pain in the lower abdomen, or with anal cramping or diarrhea, two days before your menstrual period until two days after your period, and this pain gets worse one at a time, that is, progressively worse, consider the possibility of endometriosis. In addition to dysmenorrhea, often people feel painful cramping in the lower abdomen, i.e. chronic pelvic pain. Some people also present with pain during intercourse and in a fixed location, which are all signs of endometriosis. Another major symptom of endometriosis is infertility. Endometriosis can cause infertility for many reasons. Firstly, endometriosis causes adhesions to the uterus, fallopian tubes, ovaries and their surrounding tissues, resulting in obstruction of the fallopian tubes or distortion of the fallopian tubes, etc., leading to infertility. Secondly, endometriosis of the ovaries affects the development of the egg, the discharge of the egg, and the union of the egg and sperm, thus affecting fertility. Also, in patients with endometriosis, the endometrium inside the uterus is often stunted and dysfunctional, which can also affect the implantation of embryos, etc. In addition to this, there are other causes, such as immune dysfunction in patients with endometriosis, that can affect fertility function. Does endometriosis mean infertility? In fact, you do not have to worry too much, and you should not lose confidence. Clinical practice has proven that most patients with endometriosis can become pregnant through systematic treatment. In the treatment of endometriosis infertility, the advantages and disadvantages should be weighed and individualized according to the extent of the lesion, age, duration of infertility and whether other causes of infertility are combined. The ideal treatment outcome is to obtain a pregnancy and delay the progression of the disease. Experts recommend that when starting treatment for endometriosis in combination with infertility, treatment of infertility should be the first consideration. Treatment options are divided into: expectant therapy, medication, surgery, and assisted reproductive technology. For micro or mild endometriosis, no curative measures are taken and regular follow-up is known as expectant therapy. The cumulative 6-month pregnancy rate for expectant therapy is about 24% and the cumulative pregnancy rate at 3 years is 67%. The advantages of expectant therapy are economic convenience, avoidance of delayed natural pregnancy due to suppression of ovulation by drug therapy and side effects. The disadvantage is that the endometriosis lesion may gradually worsen, which in turn increases the chances of infertility. Therefore, expectant therapy should not be taken for too long a duration to avoid aggravation of the condition affecting the patient’s ovarian function and thus worsening infertility. The traditional drugs for endometriosis, such as progesterone, 17α ethinyl testosterone, progesterone, GnRHa, etc., are used to suppress ovarian function through “pseudo-pregnancy” or “pseudo-menopause” and effectively relieve the pelvic pain caused by endometriosis. This method not only fails to improve fertility, but also delays the chance of natural pregnancy due to the suppression of ovulation during drug treatment, so it is not recommended to be used alone. Surgical treatment not only clarifies the diagnosis and staging of endometriosis, but also removes visible lesions, corrects abnormal anatomical relationships in the pelvis, improves the pelvic environment, and helps to increase the pregnancy rate. Especially, laparoscopic surgical treatment has the advantages of minimally invasive, short hospital stay and fast postoperative recovery, which can be the preferred surgical method for the treatment of endometriosis. Surgery allows patients to regain fertility relatively quickly, but the level of fertility recovery decreases with time postoperatively. The vast majority of pregnancies occur within 1 year after surgery, especially within 6 months after surgery. Therefore, it is important for patients with endometriosis to take advantage of the “golden period” of six months post-operatively and actively pursue pregnancy assistance to achieve a pregnancy. In recent years, assisted reproductive technology has become an important method of treating endometriosis infertility. For endometriosis with mild or microscopic lesions, ovulation promotion combined with intrauterine insemination can improve fertility. For patients of advanced age, long duration of infertility, combined multifactorial infertility, as well as for patients with repeated failed intrauterine insemination and recurrent endometriosis, direct in vitro fertilization-embryo transfer is recommended. Besides infertility, what are the risks of endometriosis? First of all, it must be clear that endometriosis, despite its ability to metastasize and implant distantly, is a benign lesion and is generally not life-threatening. For pain, another major symptom of endometriosis, symptomatic treatment with analgesic drugs is sufficient. In the case of Xiao Li mentioned earlier, a gynecologic examination, as well as a serum CA125 test, can be performed to initially determine if endometriosis is present. If endometriosis is diagnosed, 3-6 cycles of artificial insemination can be performed first. If there is still no pregnancy, laparoscopy is recommended to clarify the diagnosis. After the operation, the prime time of 6 months should be seized and IUI should be performed as soon as possible to achieve pregnancy.