Overnight diapers are extra absorbent, with the goal of keeping your baby dry for up to 12 hours. Brands that make overnight diapers claim they are up to 25 percent more absorbent than their regular diapers. Most aren’t much bulkier, but they can be a bit more expensive than daytime disposable diapers. While you can still use regular diapers overnight, you risk the possibility of leakage or an accident occurring. Because overnight diapers are extra absorbent, children may feel less wet than with a regular diaper and will go back to sleep or sleep through the night.