Question: how many centimeters do you need to be dilated to deliver a baby?
Answer: The cervix must be 100 percent effaced and 10 centimeters dilated before a vaginal delivery. The first stage of labor and birth occurs when you begin to feel regular contractions, which cause the cervix to open (dilate) and soften, shorten and thin (effacement). This allows the baby to move into the birth canal.