Thumb inversion in newborns is usually normal due to the presence of the grip reflex in babies. There is usually no need for undue stress. However, it is also necessary to be alert to diseases such as cerebral palsy. Due to the imperfect development of the nervous system, newborns can have a grip reflex, which typically manifests itself as an involuntary clenching of the baby’s fist when the baby touches any object in the hand, making a grip reflex. This is a normal physiological reflex of babies, and there is generally no need to worry too much about it. However, if the baby is born with neonatal ischemic-hypoxic encephalopathy, neonatal asphyxia, etc., it can lead to brain damage and cerebral palsy, which can be manifested as thumb inward, knuckle flexion, elbow flexion, and other abnormal postural manifestations. If necessary, the diagnosis can be assisted by electroencephalogram, electromyogram and other related tests. It is recommended that at-risk babies with a history of this condition should be seen in a pediatric clinic in a timely manner and treated according to the doctor’s instructions.