It takes up to seven hours for a cat to give birth to a litter of kittens. Once active labor begins, the first kitten normally arrives within an hour, with about 15 minutes between the birth of each kitten.
As each kitten is born, the mother cat stimulates it to breathe by licking it with her rough tongue. She severs the umbilical cord with her teeth and often eats the placenta. During the time between the birth of each kitten, the mother rests, cleans the kittens already born and allows them to nurse. Most cats do not require any assistance in the birthing process.