6-8 hours. A four month old baby can sleep from 10 pm to 6 am. Up until four months a baby will usually be up once between 10 pm and 6 am. If a baby is not sleeping through the night by 4 months then i discuss with parents how to achieve that. A baby sleeping in your room or in your bed may not easily sleep all night.
Typical schedule. Most babies are sleeping through for six to eight hours per night at this age. Studies show that your baby is safe sleeping on his/her back. We switched to back sleeping in the 1992 and have seen the crib death rate in the country drop by 30%. Be ready for some comments from moms who did it the old way!