The cervix is normally closed and will only dilate during labor when there are regular contractions and the fetus will be delivered when the cervix is fully dilated. The cervix is the tissue that connects the uterus to the opening of the cervix. Normally, the cervix is closed, preventing germs from entering the uterus and preventing infections from occurring. During menstruation, a small amount of blood flows out of the cervix, and the cervical opening is open. Normally, a vaginal dilator opens the vagina, but not the cervix. During labor and delivery, the cervix slowly opens due to the rhythmic contractions of the uterus, and the cervix is slowly held open, all in preparation for the delivery of the fetus.