The first problem is that the pregnancy rate decreases as age increases and ovarian function may decline. The chance of having a non-integral ploidy increases significantly, resulting in an increase in miscarriage rate and stillbirths. 3. With increasing age, some related medical diseases increase, such as hypertension, diabetes and other related problems that occur with age. First, it may be related to health; second, it may be related to fertility, which may affect the process of pregnancy and affect the baby; 4. Some diseases related to pregnancy may increase, such as the increased risk of uterine fibroids, endometriosis and other diseases in women after age, which may affect fertility and also affect the increase of miscarriage rate and other problems.