What is spontaneous miscarriage? A miscarriage is defined as a termination of pregnancy at less than 28 weeks or a fetus weighing less than 1000g. If the pregnancy is terminated by artificial factors such as surgery or medication, it is considered an induced abortion; while a miscarriage caused by natural factors is called a spontaneous abortion. What should I do if I have had 1 spontaneous abortion in the past? There is a 20% chance of spontaneous abortion for normal couples. Couples with only one history of spontaneous abortion do not need to be nervous and are advised to take a break of 6 months and prepare for pregnancy again after a preconception health check. If you are pregnant, it is better to have an early check-up and if necessary, to have a fertility treatment. What should I do if I have had 2-3 spontaneous miscarriages in the past? Those who have had 2 or more consecutive spontaneous miscarriages are called habitual miscarriages or recurrent miscarriages. In this case, both spouses should be examined for the cause of spontaneous miscarriage and treated for the cause to avoid another miscarriage. What does the screening for the cause of recurrent miscarriage include? Reproductive tract anatomical abnormalities: ultrasound, hysterosalpingography or hysteroscopy to exclude endometrial polyps, submucosal fibroids, saddle-shaped uterus, longitudinal uterus, double uterus; endocrine examination: sex hormone six, luteal phase progesterone, thyroid function, oral glucose tolerance and insulin release test; genetic examination: karyotype examination of both spouses, karyotype examination of aborted embryos; examination of infectious factors. Immunological tests: blood group (ABO and RH), reproductive immune antibodies (anti-endometrial antibodies, anti-cardiolipin antibodies, anti-sperm antibodies, etc.) of both partners; routine semen and malformation rate of the male partner, and if necessary, DNA integrity of the male partner’s sperm. How to treat and prevent recurrent miscarriage? Couples with recurrent miscarriage should have a comprehensive examination of the cause of miscarriage. If a clear cause is found, pregnancy can be treated for the cause; if there is no clear cause and it is an unexplained recurrent miscarriage, pregnancy can be treated with the husband’s lymphocyte immunotherapy. If the cause is identified and pregnancy is planned, it is recommended to monitor ovulation with vaginal ultrasound, estimate the time of ovulation and guide intercourse, and start treatment such as luteal support immediately after ovulation.