The causes of cerebral palsy are very complex, and although some of them are clear, some are still unknown. It is generally believed that any harmful factor that affects the formation and development of the brain during the fetal to neonatal period can lead to cerebral palsy. In particular, it should be emphasized that fetal brain hypoxia or insufficient blood perfusion to the brain is the most important factor causing cerebral palsy. According to several domestic sources, the main risk factors for cerebral palsy in China are: fetal growth retardation, prematurity, low birth weight, asphyxia, and nuclear jaundice. 1.Prenatal factors: pathogenic factors that appear during fetal development to 4 weeks before delivery. (1) Infection: rubella virus infection, in addition to cardiovascular effects, also mostly involves the central nervous system, such as eye and hearing damage and microcephaly and severe psychomotor retardation, etc. Cytomegalovirus infection is a neurotoxic virus, transmitted in utero, the incidence of infection is 0.2%-2.2% of all live infants, the clinical manifestations in the neonatal period or infancy are mainly hepatosplenomegaly, thrombocytopenia, microcephaly The clinical manifestations during the neonatal period or infancy are mainly hepatosplenomegaly, thrombocytopenia, microcephaly, high direct bilirubin, etc. In 5%-15% of infected infants with no symptoms, such as sensory, motor and hearing loss and periventricular calcification are important diagnostic factors. Congenital Toxoplasma gondii infection can be transmitted to the fetus via the placenta during the first trimester of pregnancy, which is a more serious but less common condition. (2) Fetal circulatory and vascular diseases: acute hypovolemia, massive bleeding in the mother due to placenta praevia, acute diffuse intravascular coagulation in twin fetuses, maternal anemia, coagulation disorders, and gestational toxicity can all cause disorders of fetal cerebral blood supply. (3) poisoning: taking certain drugs during pregnancy, drinking alcohol, smoking, mother or fetus with metabolic diseases, such as diabetes, phenylketonuria, etc., can directly or indirectly affect the development of the central nervous system of the fetus, the occurrence of placental abruption, low weight babies and brain development malformations. 2, perinatal factors: pathogenic factors that occur from 4 weeks before birth to 1 week after birth. (1) Asphyxia: Perinatal diseases and prenatal diseases cannot be separated. Most children with cerebral palsy may have impaired brain development as early as before birth, which makes them more vulnerable to the reaction at birth and thus becomes a cause of disability. It has been reported that 36% of cerebral palsy cases may be related to birth asphyxia. (2) Intracranial hemorrhage: asphyxia and hypoxia are the main causes of intracranial hemorrhage in newborns, and the incidence of preterm infants is greater than that of term infants, indicating that preterm infants are also an important factor leading to intracranial hemorrhage, especially in very low birth weight newborns with gestational age less than 32 weeks and weight <1500g, and most of them are subventricular and intraventricular hemorrhage, accounting for about 90%. Intracranial hemorrhage is also sometimes due to birth injuries, especially in children with a history of obstructed labor and a history of perinatal hypoxia. Intracranial hemorrhage and asphyxia due to ischemia and hypoxia are causally related to each other and are the main causative factors of perinatal cerebral palsy. (3) Preterm birth: The cause of preterm birth is still not clear. Studies have shown that cytotoxin-mediated increase in TNF levels in blood and amniotic fluid during fetal co-infection can lead to an increase in PGF2α levels in blood and amniotic fluid, which induces inevitable preterm birth. In preterm infants, cerebral lesions are seen as periventricular leukodystrophy, mostly in the vicinity of the lateral ventricles bilaterally. In full-term infants, brain lesions are mainly in the cortex and basal ganglia. (4) Nuclear jaundice: nuclear jaundice caused by severe jaundice, its increased blood bilirubin deposited in the brainstem and basal ganglia, its lesions lead to the emergence of tardive dyskinesia and hearing loss and other clinical manifestations, generally occurring in the first 48 hours to 4 days after birth. 3. Postnatal factors: The causative factors that appear within one month after birth. Postnatal factors account for about 10% of the causative factors of cerebral palsy, and are mostly caused by infections such as encephalitis, meningitis, CO and mercury poisoning, trauma from various causes, and convulsions.