Adenomyosis is the presence of ectopic endometrial glands and mesenchyme within the myometrium, resulting in abnormal proliferation of the surrounding myometrium. The ectopic endometrium is located within the myometrium at least 2.5L from the endometrium-myometrium junction. It can occur in all parts of the uterus, but involvement of the posterior wall is most common. The relationship between adenomyosis and infertility has not been clearly established. Patients with severe adenomyosis have a decreased chance of successful conception with assisted reproductive techniques. A French study looking at MRI images of the subendometrial “zone of attachment” in 152 infertile women found that its thickness correlated with IVF transfer success, with no adenomyosis when the thickness was <5 mm and only 2% IVF embryo transfer success when the maximum thickness was >10 mm.1 Small sample studies or case reports It has been found that adenomyosis may be associated with low fertility, and studies have found that fertility is restored after conservative treatment of adenomyoma.2-4 However, it has also been suggested that adenomyosis is not associated with low fertility because of the factors associated with the development of adenomyosis and multiple births. No consensus can be reached on the best treatment option for patients with adenomyosis combined with infertility. The treatment options include pharmacological therapy, laparoscopic or cesarean excision of adenomyoma, surgery combined with pharmacological therapy, uterine artery embolization, and magnetic resonance-guided focused ultrasound, but evidence-based medical evidence for RCT is lacking. (i) Drug therapy Gonadotropin-releasing hormone agonist (GnRHa) is recognized as the drug of choice. the mechanism of GnRHa in the treatment of adenomyosis is unclear. the GnRH agonist can transiently inhibit the hypothalamic pituitary gonadal-ovarian axis, resulting in a decrease in estrogen levels in the body, leading to atrophy of the ectopic lesion, reduction in uterine size, and reduction in symptoms. In addition, GnRHa may increase the tolerance of the endometrium. A study on the relationship between the use of GnRHa in the treatment of adenomyosis and the rate of conception showed that 9 pregnancies occurred spontaneously after drug administration, and all pregnancies occurred between 1 and 12 months after the completion of treatment, showing that the use of GnRHa in patients with adenomyosis combined with reduced fertility can promote conception, and the authors recommend that if pregnancy does not occur within 6 months after the completion of drug treatment or after the first menstrual cycle after drug treatment In China, clinical observations have shown a 75.0% (9/12) conception rate in patients with adenomyosis combined with infertility treated with GnRHa.6 Khan KN et al7 found a significant reduction in the number of macrophages in the endometrium after treatment with GnRHa in women with adenomyosis with low fertility, which improved the success rate of embryo transfer. Mijatovic et al8 data showed that the pregnancy rate of infertile patients with adenomyosis treated with GnRHa followed by IVF or ICSI was similar to that of infertile patients without adenomyosis. (ii) Conservative surgery Although cases of pregnancy have been reported in patients with adenomyosis infertility treated with surgery, the pregnancy rate of the former is lower when comparing conservative surgery with pharmacological treatment. Possible reasons for this are: (1) low surgical clearance rate due to extensive lesions; (2) difficulty in avoiding postoperative pelvic adhesions, uterine malformations, uterine adhesions, and reduction of uterine volume, which may affect conception. (3) It is difficult to avoid endometriosis lesions entering the myometrium during surgery, increasing the probability of endometrium entering the myometrium with an incidence of 30%. (4) Compared with myomectomy, the blood supply around the uterine incision is poorer, the tension of the myometrium is reduced, and the risk of postoperative uterine rupture is likely to increase. A clinical observation data showed that after treatment of adenomyosis with conservative surgery, 9 cases of spontaneous pregnancy, one of which had uterine rupture at 12 weeks of gestation. Pelvic denervation treatment: In recent years, foreign scholars have used open or laparoscopic presacral neurectomy (PSN) and uterine neurectomy (UNA) to treat primary and secondary dysmenorrhea, and achieved better results. Principle: The sensory nerve conduction pathway of the pelvic organs reaches the spine from the lower abdominal plexus located in front of the sacrum, so cutting the presacral nerve trunk can block the nociceptive conduction pathway. Both procedures cut off most of the cervical sensory nerve fibers, thus reducing uterine pain. It is indicated for patients who require preservation of the uterus when medication is not effective and may also improve pregnancy rates. However, there is a risk of postoperative complications related to parasympathetic dysfunction, such as diarrhea, constipation, urinary symptoms, vaginal dryness, unpleasant intercourse or extreme arousal. These symptoms can be significantly improved with or without special treatment. Other rare complications include right iliac artery injury, celiac ascites and unilateral labial edema. (iii) Combined conservative surgery and drug therapy Because drug therapy can briefly inhibit the growth of ectopic endometrial lesions, while surgical treatment of endometriosis-related disease is approximately 50% effective, combined conservative surgery and drug therapy (GnRHa or danazol) is used in clinical practice. In one study, 165 patients with symptomatic adenomyosis treated with conservative surgery were divided into a GnRHa combination therapy group and a surgery-only group, and the results showed that the 2-year follow-up revealed a higher rate of symptom improvement and a lower rate of symptom recurrence in the combination therapy group than in the surgery-only group, but there was no significant difference in the clinical pregnancy rate between the two groups (79.5% in the combination therapy group versus 74.1% in the surgery-only group However, there was no significant difference in the clinical pregnancy rate between the two groups (79.5% in the combined group versus 74.1% in the surgery-only group), nor in the successful delivery rate (72.7% in the combined group versus 63.0% in the surgery-only group). Thus, the combined surgical and pharmacological regimen had a higher rate of symptomatic improvement and a lower rate of recurrence. Therefore, it is considered that the combination treatment option is recommended for patients with severe adenomyosis combined with infertility.10 (iv) Uterine artery embolization (UAE) Embolization of the blood supplying arteries on both sides of the uterus destroys the focal vascular bed and inhibits vascular regeneration, causing necrosis of the ectopic endometrial tissue, compression of the myometrium due to volume reduction and closure of the original tiny channels, and loss of access of the normal endometrium to the myometrium, thus reducing the the possibility of recurrence. After uterine artery embolization, although the normal functional endometrial layer may also become mildly necrotic, it can regrow and resume normal function after vascular collateral circulation is established. In contrast, in ectopic endometrium, the necrosis is irreversible because of the lack of basal lamina support, and the necrotic myometrial lesions cannot regrow for therapeutic purposes. pregnancy and delivery can still occur after UAE for adenomyosis. kim et al11 reported 8 pregnancies in 6 patients treated with UAE, 3 of whom had endometriosis and 1 with both endometriosis and uterine fibroids. 1 One patient with endometriosis had 2 pregnancies, one up to 34 weeks and one full-term pregnancy. All of the newborns were born at full term and healthy, except for one who had a premature rupture of membranes at 34 weeks (birth weight of 1850 g). Despite the small number of cases, the authors concluded that polyvinyl alcohol pellets for UAE do not affect fertility or pregnancy outcomes. Although no effect of uterine artery embolization on fertility has been reported, in recent years a comparison of fertility after myomectomy and uterine artery embolization has been reported, with the observation that patients in the myomectomy group had greater fertility compared to the uterine artery embolization group at 2 years after treatment. Although there is no report on the effect of UAE on fertility, scholars believe that the fertility outcome after conservative surgical treatment is better than that of UAE, and recommend conservative surgical treatment and less UAE for patients with adenomyosis who desire fertility. (E) Magnetic resonance-guided focused ultrasound () MrgFU refers to the use of high-intensity focused ultrasound under MRI guidance to cause protein denaturation of local lesions at a temperature of 55 degrees or higher MrgFU is a therapeutic method that causes irreversible cell death through coagulative necrosis, resulting in necrosis of the endometriosis lesion. Rabinovici et al12 reported 9 patients treated with MrgFU, one of whom was pregnant after MrgFU and delivered vaginally a full-term healthy live female child with a birth weight of 3.050 kg, but such reports are still anecdotal and there is a lack of clinical studies with large samples. In conclusion, the main treatment options for adenomyosis infertility are pharmacological and pharmacological combined with surgical treatment, but new methods such as UAE and MrgFU have been tried in recent years, but the efficacy is still uncertain. Since the management of adenomyosis infertility is mainly reported by case reports and retrospective data, there is a lack of RCT evidence. Therefore, the management of adenomyosis infertility is still highly controversial.