Generally, babies can sit in safety seats at around 6 months old. The specific situation varies from person to person and cannot be judged in a single way. It should be judged according to the speed of the baby's development.
Before 6 months old, the baby's spine is not fully developed, and the waist and back muscles are not strong enough to support it. Therefore, it is not recommended to sit in a safety seat to avoid scoliosis. Most babies will gradually form cervical lordosis or thoracic kyphosis in the spine around 6 months old, and the strength of the waist and back will gradually mature. Safety seats can be used, and most of them will not cause any harm to the baby. When babies use safety seats, they need to pay attention to safety.