The first menstrual flow after miscarriage may be caused by endocrine disorder, endometrial damage or uterine adhesion, etc. You need to go to the hospital for a review to determine what causes it and treat it accordingly. 1. Endocrine disorder: After miscarriage surgery, due to anxiety, anxiety and other bad emotions or irregular rest and rest, it may lead to endocrine disorder, causing early or postponed periods and too little menstrual blood. Therefore, attention should be paid to ensure adequate rest, pay attention to a light diet, avoid eating cold and stimulating food, and also to ensure a relaxed mood, generally can slowly recover; 2, endometrial damage: abortion surgery will lead to a certain degree of endometrial damage, the endometrium is too thin will lead to menstrual blood thinning, can be under the guidance of doctors by taking sex hormones to promote the growth of the endometrium, so that the amount of menstrual blood After abortion surgery, the destruction of the endometrium will cause adhesions in the uterine cavity, which will lead to the inability to discharge menstrual blood smoothly and reduce the amount of menstrual blood. Hysteroscopic separation of uterine cavity adhesions can be performed to restore normal menstrual flow after the operation. 4. Post-operative infection: Improper care after abortion may cause bacterial infection and inflammatory stimulation may cause irregular vaginal bleeding, which needs to be distinguished from menstruation. Local topical metronidazole suppositories can be used under the guidance of doctors, and oral antibiotics such as cefixime, levofloxacin and roxithromycin can also be taken; 5. Uterine cavity residue: failed abortion or unclean intraoperative uterine clearance, resulting in postoperative residual pregnancy sac, may also appear a period of postoperative vaginal bleeding, rather than menstruation, which needs to be identified and promptly go to the hospital for consultation. Therefore, 1 month after the abortion, you need to go to the hospital to review the ultrasound, through which you can observe the situation in the uterine cavity and exclude incomplete suction or residual pregnancy tissue, in order to avoid causing other damages.