During clinic visits, we often encounter patients who say that their periods are particularly low. After detailed medical history, we found that they all have one common feature – repeated abortions. The normal uterus is surrounded by a thick muscle with a cavity in the middle, and the tissue covering the surface of the cavity is the endometrium. When the endometrium is damaged by mechanical injury or infection and other pathological factors, resulting in local loss or fibrosis of the endometrium, leading to adhesions in the front and back walls of the uterine cavity, the cavity loses its normal shape, which is called “uterine adhesions”. The medical term for such adhesions of the uterine cavity and/or cervix that occur after abortion is Asherman syndrome. Why does the menstrual flow become less after Asherman’s syndrome? The normal physiological state of the uterine cavity is that the anterior and posterior walls are in contact and united, and adhesions do not occur even when the endometrium is exfoliated during menstruation because the basal layer of the endometrium is intact and functioning properly. The endometrium is divided into a basal layer and a functional layer, which in turn includes a dense layer and a spongy layer. During the normal menstrual cycle, the functional layer peels off to form menstruation, and these peeled off functional layers flow out of the uterine cavity with menstruation, and in the next cycle the reserve cells in the basal layer begin to form functional layers again in preparation for the next menstruation. When the basal layer of the endometrium is damaged, the formation of the functional layer is blocked, thus affecting menstruation, and these damaged endometrium are replaced by adhesive bands, the endometrial glands become very sparse or inactive, and most of the endometrial tissue lacks blood vessels and is scarred and unresponsive to hormonal stimulation. This is why patients find that their menstrual flow becomes less frequent after abortion. Before having an abortion, doctors always take great pains to tell patients that abortion may cause damage to the endometrium, may affect menstruation, may lead to infertility and other risks. Second, how does abortion lead to Asherman syndrome and how does it cause infertility? The endometrium is the “soil” in which the fertilized egg takes root, and a fertile “soil” can ensure that the fertilized egg takes root and grows strong. As the embryo is planted on the endometrium, the endometrium will be damaged when the embryo is sucked out by the spatula or suction tube. When these stimuli damage the basal layer of the endometrium (which is the backup for the formation of menstruation each month), the formation of the basal layer to the functional layer is blocked. This prevents the endometrium from growing and shedding regularly, and these stimuli cause a pathological reaction in the basal layer, leading to fibrinogen exudation and deposition in the uterine mesenchyme, resulting in cavity adhesions. On this pathological basis Asherman syndrome occurs. The endometrium is the soil for embryonic development, and the formation of adhesions will make the soil infertile and affect the “settlement” of the fertilized egg, leading to infertility; even if the endometrium is left to implant, the lack of blood supply and hormonal support will not provide sufficient nutrients for the embryo, leading to spontaneous abortion, embryonic abortion and other adverse pregnancy outcomes. With that said, it is very understandable how Asherman syndrome can lead to infertility. The main cause of uterine adhesions is injury, such as repeated uterine scratching during abortion, cessation of embryonic development or clearance after induction of labor, followed by infection such as tuberculosis of the uterine cavity. The literature reports that the incidence of uterine adhesions caused by repeated abortions and scrapings is as high as 25-30%, which has become the main cause of reduced menstrual flow and secondary infertility. Third, after repeated abortions, what symptoms need to be alerted to the occurrence of Asherman syndrome? (1) Low menstrual flow or even amenorrhea: If the uterine cavity is partially adhered and/or the endometrium is partially destroyed, the menstrual flow is low, but the menstrual cycle is normal. In cases of complete adhesions, amenorrhea can occur, which can be very long and does not cause withdrawal bleeding with estrogen or progestin treatment. (2) Periodic abdominal pain: Patients may experience sudden spasmodic pain in the lower abdomen, which usually lasts for 3-7 days and then gradually decreases and disappears, and at an interval of about one month, periodic abdominal pain occurs again and progressively worsens. (3) Infertility and recurrent miscarriage: secondary infertility is likely to occur after uterine cavity adhesions, and recurrent miscarriage and preterm delivery are likely to occur even after pregnancy. As a result of uterine cavity adhesions, the endometrium is damaged and the volume of the uterus is reduced, which affects normal embryo implantation. It also affects the survival of the fetus in the uterine cavity until full term. When these symptoms appear, this also means that the patient may have Asherman syndrome. 4. Having said that, the most important concern should be how Asherman syndrome should be treated clinically? So far, the treatment of uterine adhesions has been a heartache and headache for doctors. The “heartache” is the impact of this disease on the patient’s menstruation and fertility, and the “headache” is that there is no better way to deal with it. Therefore, if you are not planning to have BB, you should make sure you have good contraception, good contraception, good contraception! It is important to say it three times! According to the nature of adhesions, there are membranous adhesions, muscular adhesions and connective tissue adhesions; according to the degree of adhesions, there are mild, moderate and severe adhesions, of course, the treatment of different nature and different severity of adhesions are different, but in general, it is to restore the uterus to normal or approximately normal under hysteroscopy as much as possible, to further restore menstruation, to prevent further adhesions, to promote endometrial repair and proliferation and to improve pregnancy rate. Patients who present with symptoms (e.g. abdominal pain, menstrual abnormalities, etc.) or fertility-related problems should be treated. However, each patient will have a different treatment plan due to the degree and goals of each patient. When the treatment is aimed at restoring the physiological function of the endometrium and restoring menstruation, mechanical adhesion separation under hysteroscopy or adhesiotomy under electrosurgery is used for patients with mild to moderate cavity adhesions. In patients with severe cavity adhesions, the endometrium has been severely damaged and there is very little endometrium left. It has been reported that patients with severe cavity adhesions are prone to re-adhesions after treatment and the incidence of re-adhesions after hysteroscopic adhesion separation is as high as 6.5%. In other words, patients with severe uterine adhesions, even after multiple surgeries to reconstruct the uterine anatomy, are not guaranteed to have normal fertility, just like desert soil, where it is difficult for grass to grow. No matter how Asherman syndrome is treated, the damage to the patient is irreversible. Foreign scholars who have studied patients who have developed Asherman syndrome have concluded that despite the availability of advanced hysteroscopic procedures, treating moderate to severe Asherman syndrome remains very challenging. In addition, even if pregnancy is possible after treatment, there may still be high-risk complications including miscarriage, preterm delivery, intrauterine growth restriction, placental adhesions, and even uterine rupture. Having said that, avoiding abortion, especially repeat abortion, is the best and most effective way to prevent uterine adhesions and Asherman’s syndrome. Don’t let “painless” abortions hurt you!