Newborns born at a gestational age of less than 37 weeks are referred to as preterm infants. And newborns with birth weight less than 2500g are collectively called low birth weight babies, including full-term low birth weight babies and preterm low birth weight babies. I. High-risk factors of preterm birth 1, lifestyle and social factors: maternal age is related to preterm birth, age less than 18 years old or more than 40 years old is a high-risk group. Malnutrition, low weight, low socioeconomic class, smoking, drug and alcohol abuse significantly increase the risk of preterm birth, and some also increase the risk of brain damage in preterm babies. 2, Pregnant women with previous history of miscarriage and preterm birth. 3, combined medical and obstetric complications: acute and chronic medical diseases such as heart disease, chronic hypertension, severe anemia, hyperthyroidism, diabetes, pyelonephritis, viral infection, periodontal disease, etc.; obstetric complications including placenta praevia, placental abruption, amniotic fluid, premature rupture of membranes, multiple pregnancy, cholestasis, prenatal hemorrhage, pregnancy eclampsia, chorioamnionitis, etc. 4, uterine malformation: double uterus, bicornuate uterus, longitudinal uterus, uterine fibroids, relaxed inner cervical opening, etc. 5, trauma, fatigue, excessive frequent sex can also lead to premature birth. Third, the problems faced by preterm babies after birth 1, early problems faced ① body temperature off: preterm babies’ thermoregulatory center is not well developed; the body surface area is large relative to body weight, so it is easy to dissipate heat; less subcutaneous fat, especially brown fat, lack of skeletal muscle cold response, resulting in less heat production, and the sweat glands are not fully developed, not easy to dissipate heat through sweating. Therefore, the body temperature of premature babies tends to change more significantly with the ambient temperature. Birth weight less than 2,500g especially less than 2,000g premature baby, after birth more need to sleep in the incubator to ensure the appropriate temperature and humidity, but also facilitate the observation of the condition. ② respiratory off: premature baby’s respiratory center, respiratory muscle development are immature, manifested as irregular breathing, cough reflex is weak, but also occur airway secretions are not easy to discharge, apnea, etc., combined with respiratory diseases such as respiratory distress syndrome, pneumonia, etc. can easily lead to respiratory failure. Jaundice: Because of the low metabolism of bilirubin in preterm babies, the long time of meconium excretion, and the lack of protein synthesis capacity of the liver, the jaundice of preterm babies lasts for a long time, and their blood-brain barrier is not well developed, and the free bilirubin in the blood is easy to pass through the barrier, leading to bilirubin encephalopathy, so preterm babies with jaundice should be treated with early intervention to avoid brain damage. Infection: Most preterm babies are born prematurely because of chorioamnionitis, and preterm babies are born with low humoral and cellular immunity, which makes them susceptible to infections, which can easily spread to the whole body. The infection can be heavy or light, but in heavy cases it leads to severe pneumonia, sepsis, diffuse intravascular coagulation, intracranial infection, etc. The progress of the disease is also faster than in full-term babies, and sometimes there is often no obvious aura. ⑤ Nutrition: Premature babies are born with inadequate nutrition, and their nutrition must be properly grasped later in life, otherwise they cannot achieve catch-up growth. Premature babies have insufficient gastrointestinal power and gastrointestinal hormone secretion, coupled with early postnatal infections, jaundice and other diseases, so early nutrition via the gastrointestinal tract is often unable to keep up with the need to give extra-gastrointestinal that is intravenous nutritional support therapy to meet the body’s nutritional needs. But eventually, the transition to complete gastrointestinal nutrition is required before discharge. The choice of gastrointestinal nutrients needs to be determined according to the baby’s gestational age, weight, and physical development. (6) Brain damage: Premature babies have a subventricular embryonic germinal layer matrix closely related to brain development, so they are prone to intracranial hemorrhage and cerebral white matter softening, infection, nutritional deficiency, coagulation dysfunction, etc. can lead to brain damage, while most of them have no obvious manifestation from the outside, so they must do cranial imaging and other clear situations, and serious ones will image intellectual and motor development. 2. Problems faced in the late stage ① Nutrition: nutritional problems are always with preterm babies, under-nutrition and over-nutrition are undesirable. To achieve proper nutrition, the guidance of medical staff should be followed at the time of discharge to choose a suitable feeding method for the baby. The choice at discharge varies for different gestational ages and weights, with breast milk, post-discharge formula for preterm babies, and formula for full-term babies available. As your baby grows, you will also have to adjust the feeding method according to the weight, head circumference and length indicators for each period. Insufficient nutrition leads to anemia, infection, inhibited brain development, inattention, learning difficulties, etc.; and excess nutrition leads to cardiovascular disease (hypertension, stroke), obesity, diabetes, etc. in adulthood. ②Infection: Premature babies are more susceptible to infection than full-term babies, therefore, they still need to be closely monitored after discharge from the hospital, with good room ventilation, disinfection of milk utensils, personal hygiene, etc.; if the person in contact with the baby has a cold or other problems, they should temporarily avoid contact with the baby; if the breastfeeding mother has a cold or other infections occur, breastfeeding should be suspended. ③ Neurological development: this issue is very important and determines the quality of the baby’s survival and should not be ignored. Brain development persists after the birth of a premature baby, and many factors can affect its development. After discharge from the hospital, corresponding neurological interventions can be given according to the baby’s specific situation, and post-discharge follow-up is especially important. Experienced specialists will determine the baby’s condition through physical examination and relevant auxiliary tests and make correct guidance. It can be seen that preterm babies are not just a little premature, they face many realistic problems after birth, not necessarily every hurdle is encountered, are very problematic, but must be closely monitored and disposed of in a timely manner in front of every hurdle, in order to take good care of preterm babies. For babies with birth weights greater than 2000g, parents and some medical staff tend to ignore them easily due to their relatively large gestational age and heavy weight, resulting in more serious clinical conditions that should be taken seriously.