The Birth is when the baby want to go out of the uterus.

The Birth is complicated, first the walls of he uterus start to contract, then the cervix gets wider to enable the baby to come out of the uterus, next the amniotic sac breaks and the contractions push the baby into the vaginal canal.

Little by little the baby is expelled, headfirst, throught the vagina.Once the baby it's outside , stars to brathe and the doctor cut the umbilical cord.

Finally all the rest are expelled.