Early signs of developmental abnormalities in infants include: 1. The infant’s arms and legs are often “jerked” and flexed or straightened with “abnormal force”. 2, three months can not lift the head, four months hand still clenched fist, thumb close to the palm of the hand, five months arm can not support the body, six months to support the toes when standing. 3.Seven months old cannot pronounce “ba, ma”. 4.Cowardly, less active, often appear to be frightened. 5.The head and hands shake frequently or are distressed and upset all day long, and have difficulty feeding. 6.Can’t look at the toys in front of them well or react poorly to sounds.