The optimal age for women is 25 to 28 years old, because during this period, women become more physiologically and psychologically mature, more stable in their social relationships, and more suitable to take on the role of a mother. A woman’s bones are not fully calcified until she is 23 to 24 years old. If a woman becomes pregnant before her bones have fully calcified, not only does she need a lot of calcium for herself, but she also has to divide some of it to supply the fetus with growth and development, and if the calcium supplementation is not timely, calcium deficiency may occur. Calcium deficiency affects the health of the body and can also lead to abnormal development of the fetus. The risk of natural childbirth in advanced maternal age is high, with advanced maternal age and precious fetus, due to high mental stress. The reduced elasticity of the pelvis and ligaments and cervical tissues, reduced perineal extensibility and decreased physiological compliance in older pregnant women often lead to prolonged labor, which increases the risk of fetal distress. The incidence of placenta praevia during pregnancy has been reported to be higher in older women than in non-older women. The incidence of hypertensive disorders in pregnancy in older women is 4-5 times higher than in non-advanced women because of the progressive increase in vascular endothelial damage with age, which in turn decreases the production of diastolic factors and increases the production of systolic factors to the point of causing peripheral vasospasm and ischemia of the uterus and placenta, thus inducing hypertensive disorders in pregnancy. At the same time, the uterine muscle fibers are edematous, congested, hypoxic, broken and contractile, and prone to postpartum hemorrhage. With age, pregnant women are more likely to have insulin deficiency and insulin resistance, as well as decreased insulin receptors and insulin affinity. They are prone to gestational diabetes. In addition, due to certain mental factors, such as emotional stress, strong expectation of the fetus, etc., the sympathetic nerve excitement, which increases the secretion of adrenaline, so that the muscle fibers of the uterus can not contract, inhibit the contraction of muscle fibers can not make the uterine wall blood vessels more tortuous, and therefore can not play the role of compression of the uterine wall vessels to stop bleeding. This inevitably prolongs the duration of labor, puts the fetus at risk and makes the uterus contract poorly, causing postpartum hemorrhage.