Babies need a lot more sleep than adults. A newborn infant needs up to 18 hours of sleep each day. A baby spends about nine hours in REM sleep. Five–year–olds need 11–13 hours of sleep each day. A five–year–old spends about 2 hours in REM sleep. Teenagers need 9–10 hours of sleep each day. Pregnant women need more sleep than other adults. Many people think that elderly people need less sleep than younger adults, but that is not true. Most adults do well with 7–9 hours of sleep.