There is no fixed time for how many days a premature baby can get through a difficult time, which is mainly related to the gestational age and birth weight of the premature birth. Premature infants generally need to get through difficulties in respiration, feeding, temperature, and infection. Premature infants have an underdeveloped respiratory center and are prone to irregular breathing and even apnea; the digestive system is intolerant to feeding, sucking and swallowing are uncoordinated, and necrotizing small intestine colitis may occur; preterm infants have an unstable thermoregulatory center and poor peripheral circulation, and are susceptible to external temperature, so they should be put in an incubator if necessary; preterm infants have poor resistance and have a higher chance of infection, and are prone to pneumonia Even sepsis, etc. Therefore, premature babies should be at least 37 weeks old, weigh 2.5 kg, have no other diseases, such as obvious jaundice, infection, etc., and have the strength to suckle and not choke and cough, which mostly suggests that they can pass the difficult time. In addition, premature babies should be breastfed as early as possible. Breast milk contains a large amount of protein, essential fatty acids, trace elements and immune components, which can improve the infant’s resistance in order to pass the difficult time as early as possible.