4-month-old baby developmental delay is mainly manifested in slow weight gain, length growth is not obvious, can be analyzed in physical, motor, language, intelligence and other aspects. 1. Physical: compared with the same age, the baby’s weight growth is slow, the length of the growth is not obvious, may be a reduced diet, the mother can pay close attention. 2. Movement: relatively dull, will not roll over, legs, eat hands and other movements, will not focus on toys, do not pay attention to people, eyes will not follow objects. 3. Language: visual and auditory development is slow, no response to sounds and calls, unable to make umm or ah sounds, and no response when adults tease the baby. 4. Intelligence: Can’t suck on the pacifier when eating. 4-month-old baby developmental delay may also have other symptoms, found that the baby has the above symptoms of developmental delay, it is recommended to go to the hospital for examination, and actively cooperate with the doctor for treatment.