Repeated miscarriages are examined for the following causes: 1. fetal factors: if available, try to keep the miscarried tissue after the miscarriage and send the villi for chromosome culture or DNA testing to detect whether the miscarriage is caused by chromosome or DNA abnormalities in the fetus itself; 2. maternal related tests: hormone testing mainly focuses on female sex hormones, prolactin, androgens, thyroid function, and glucose for abnormalities in glucose and glucose metabolism. In addition, hysteroscopy or fallopian tube imaging is needed, combined with ultrasound to assess whether there are any morphological abnormalities in the uterine cavity, and hysteroscopy to rule out uterine malformations and uterine adhesions, which are also common causes of miscarriage; 3.