High-risk children include: 1) abnormal gestational age, overdue children with gestational age of 42 weeks; 2) abnormal weight, huge children with weight of 4000g; 3) abnormal delivery, cesarean section, use of forceps, and abnormalities such as negative pressure suction, stalled labor, and emergency delivery; 4) maternal abnormalities, such as placenta abruptio, placenta praevia with hemorrhage, premature rupture of membranes, gestational diabetes, gestational hypertension, gestational anemia, gestational combined hyperthyroidism or hypothyroidism, gestational combined syphilis, gestational combined hepatitis, gestational combined thrombocytopenia, and prenatal fever, etc. All these children are considered high-risk after birth.