Whether it is better to have a child early or late cannot be generalized, but it is better to have a child at an age suitable for childbearing and well-prepared in all aspects. For women of childbearing age, from the perspective of eugenics, the optimal age for childbearing is between 23 and 35 years old, it is not good to have children too early or too late, and it is better to have children at a suitable age for childbearing. For childbearing, the age factor must be taken into consideration. If the mother is too young, she is not yet fully developed, which will have an adverse effect on the development of the child. If the mother is too old, her eggs will gradually decline and the function of her ovaries will decrease, with a consequent increase in the chances of genetic diseases and an increase in the occurrence of pregnancy disorders. In the period of 23-30 weeks of age, the woman’s body in addition to age, in the psychological and economic aspects of the preparation, all aspects of the right time to have a child is best.