As babies grow older, their total sleep time gradually decreases, gradually shortening the daytime sleep time and gradually lengthening the nighttime sleep time. Most babies can only sleep for 6-8 hours at night when they are 3 months old (or weigh 5.5-6 kg). About 2/3 of babies can achieve more regular sleep before 6 months of age and do not wake up frequently at night. However, there are individual differences among children. Each child's sleep pattern is different. For example, some healthy...