The 42-day postpartum checkup is not only for the mother to return to the hospital for a checkup, but also for the baby to be examined by a pediatrician to monitor the baby’s growth and development. 42-day checkup is significant for newborn babies, and it is the beginning of growth and development monitoring for the baby. The 42-day checkup includes: 1. weight, which is an important indicator to determine the baby’s physical development and nutritional status. 2, height (length), is a major indicator of the baby’s bone development. 42 days after the birth of the baby should use the standard length measuring instrument for standardized measurement. 3, head circumference, reflecting the baby’s brain development, the size of the brain volume, is also an important indicator of the baby’s development. 4.Breast circumference, evaluating the development of baby’s chest, including the development of lungs, the development of thorax and the degree of development of chest and back muscles and subcutaneous fat. 5.Neurological examination, including motor development ability and neurological reflex examination, etc. The neurobehavioral score of the baby is a key point to detect early brain development abnormalities, and early detection and intervention treatment can significantly reduce the incidence of cerebral palsy and disability rate. 6. Other physical examination contents, fontanelle, subcutaneous fat thickness test, upper and lower volume measurement, hearing screening, genetic metabolic disease screening, etc. In addition to growth and development, neurobehavior and other indicators, some hospitals also cover education on feeding methods, family care and the sequence requirements for adding complementary foods, etc. Due to differences in geography and hospitals, the content of the 42-day checkup for babies is not entirely consistent. The 42-day checkup is very important to monitor the baby’s growth and development, guide feeding, especially for premature babies, babies with a history of asphyxia, family history of abnormalities can be detected early, early intervention and treatment to reduce the amount of sequelae.