It is a folk saying that the mammoth period of an infant is generally recognized as the first three months of life. Mastodon is generally referred to as the stage of vigorous growth and development, and most infants grow most rapidly in the first three months, especially in the development of their body structure. Often, weight can double relative to birth weight and length can increase by more than 10 centimeters in the first three months. During the first trimester, infants usually show more milk intake and are more noisy. Therefore, parents should take care of the baby’s diet and sleep when the baby is going through a hardening period. In the first three months of the baby’s life, it is necessary to take care of the baby and feed the baby according to the need to ensure that the baby’s milk intake, so as not to affect the baby’s normal development. Generally speaking, the first three months of life are the growth spurt for infants. If there is any abnormality, please consult the pediatrician in time.