If a baby has an inward thumb clasp when making a fist within 3 months of age, most are normal. If after 3-4 months of age, the baby is still in a hand clenching fist with the thumb inward, the following two conditions should be noted: 1. If the thumb is simply inwardly clenched and the baby’s other development is normal, it may be that the flexor muscle tone of the hand is higher than the extensor muscle tone, and local massage can be given, and most will improve. 2. If the baby is at high risk for cerebral palsy, in addition to hand clenching fist, it is often accompanied by the performance of easy head back, difficulty in breastfeeding, body jerking, and so on. And there are high-risk factors before, during or after birth, such as prematurity, low birth weight baby, hypoxic-ischemic encephalopathy, etc. If you have any of these signs and history, you should go to the hospital promptly.