Embryonic chromosomal abnormalities In 46% of miscarried embryos, the karyotype is abnormal, so half of the miscarriages are due to embryonic chromosomal abnormalities, of which 53% are early stage miscarriages and 36% are late stage miscarriages. The earlier the spontaneous miscarriage such as biochemical pregnancy and early embryo loss, the greater the chance of embryonic chromosomal abnormalities. Embryonic chromosomal abnormalities include numerical and structural abnormalities, and the most numerical abnormality is chromosome trisomy. Chromosomal abnormalities are normal in both spouses, and chromosomal abnormalities in the fetus are associated with a high maternal age at childbirth. Structural chromosomal abnormalities including chromosomal translocations are not uncommon in both spouses, and these couples can undergo triple IVF to screen the embryos for chromosomes. Chromosomal abnormalities are predominantly from the mother (72% to 81% of cases). Couples with chromosomal abnormalities account for 3.2% of recurrent miscarriages and 0.2% of non-miscarried couples. For chromosomal abnormalities in couples, genetic diagnosis (PGD) and screening of embryos for chromosomes (PGS) are required before embryo transfer. For women with infertility and advanced age, embryo screening is recommended, especially for recurrent embryo chromosomal abnormalities. Women’s age affects spontaneous abortion, with a higher rate of spontaneous abortion in women aged 22 to 23, the lowest rate in women aged 25 to 30, and an increased rate of embryonic chromosomal abnormalities after age 30, reaching 35% in women aged 35 and 50% in women aged 40. Now that the second child is open, many women in their 40s need to worry about the incidence of such spontaneous abortions. Maternal endocrine disorders 1, luteal insufficiency Luteal insufficiency can cause poor metaphase response in pregnancy and affect the implantation of pregnant eggs. There is no gold standard for the diagnosis of luteal insufficiency. In the past, endometrial biopsy was used, such as endometrial biopsy in the secretory phase, and pathology suggesting late proliferation can be considered luteal insufficiency, but this is an invasive test and is not commonly used. The most commonly used diagnosis is that the luteinizing hormone peak to menstrual phase is relatively short if it is less than 13 days. Continuous monitoring of 2-3 menstrual cycles and finding progesterone in the luteal phase below 10ng/mg suggests luteal insufficiency. A common cause of luteal insufficiency is small follicular ovulation, in which case ovulation-promoting drugs are needed to make the follicles grow. On the other hand, patients with good ovulation who have luteal insufficiency need to be supplemented with luteal function. A proportion of patients with recurrent miscarriage have luteal insufficiency. Luteinizing insufficiency can be treated with drugs that promote follicle development and facilitate the formation of luteinizing hormone peaks during the menstrual cycle. Patients with endometriosis are often combined with follicular luteinization, which is due to abnormal luteinizing hormone production, or early onset of small follicular ovulation, or insufficient support for final follicular maturation and ovulation. In addition, luteinizing stimulation therapy can be performed: this is when chorionic gonadotropin is given after the basal body temperature rises (ovulation), 1000-5000 U, depending on the dosage form at each hospital. Smaller doses can be given intramuscularly every other day, while larger doses can be given intramuscularly every third day. On the other hand, luteal function replacement therapy can be performed, i.e. progesterone is given daily for 10 to 14 days since ovulation. A meta-analysis showed that luteal function replacement therapy was effective in recurrent miscarriage. Progesterone and estrogen, which are commonly used for fetal preservation, both have immunomodulatory effects and can induce the body to produce confinement factors, which can shift the body’s immunity from Th1 to Th2 type and allow normal pregnancy. Progesterone is very important for the maintenance of pregnancy. Progesterone is also important, but the dose should not be high, 10mg/d is not enough, but not more than 40mg/d. Blood progesterone levels are pulsatile and fluctuate very much, and it is not recommended to use progesterone levels as an indicator of pregnancy progression. 2. Polycystic ovary syndrome Polycystic ovary syndrome leads to a decrease in egg quality and endometrial tolerance. 56% of patients are hypersecreting luteinizing hormone, and the high concentration of luteinizing hormone leads to premature completion of the second meiosis of oocytes and premature maturation of oocytes. In addition, hyperandrogenemia and hyperinsulinemia in polycystic ovary syndrome are harmful to pregnancy. Treatment starts with weight control and metformin for hyperinsulinemia. Some patients with polycystic ovary syndrome have a combination of antiphospholipid syndrome, which is prone to thrombosis and is detrimental to fetal