Growth and development is an extremely complex process, basically regulated by genes, but gene expression can also be affected by various factors inside and outside the body.
Factors affecting the normal growth and development of the organism are: 1. maternal nutrition, endocrine function and diseases are closely related to the growth and development of the embryo and fetus; 2. 5, the body cells themselves can not accept the regulation of hormones or growth factors and proliferation and differentiation, will also lead to abnormal growth and development.