The developmental delay of 11-month-old babies is manifested in various ways such as physical developmental delay, motor developmental delay, mental developmental delay, etc. The developmental delay of 11-month-old babies refers to the slowing down or abnormal sequence of development during the stage of growth and development. Developmental delay refers to the slowing down or abnormal sequence of development during the growth and development stage of a baby. 11-month-old babies with developmental delay can be seen in the fact that their height is less than 73 centimeters, weight is less than 9 kilograms, and they can’t sit or stand up, can’t hold things, can’t crawl, can’t smile, can’t imitate adults’ movements, and can’t even distinguish strangers from acquaintances. If your baby has any of the above symptoms, parents should take your baby to the hospital immediately for a detailed examination and assessment to find out the cause of the growth retardation and to carry out intervention and treatment.