In the weeks immediately preceding birth, your body undergoes rapid changes, preparing for the transition from pregnancy to the delivery of your baby. For months, your baby has grown safely in your womb and now your body begins the natural steps towards bringing a new life into the world. In a healthy pregnancy, the cervix remains tightly closed until birth nears.
Time Frame for Labor Stages
In order for you give birth your cervix, the opening to your uterus, must dilate enough to allow your baby to pass through the birth canal. Dilation is measured in centimeters and many women experience a small degree of dilation one or even two weeks before going into labor. At 10 centimeters (approximately 4 inches), your doctor will prepare you for delivery.
A mucus plug fills the opening of the cervix for many months but as you near the end of your pregnancy, your cervix softens, thins and begins to open slightly. At this point, you may experience a mucus discharge, tinged with blood. This is natural and is a sign that your cervix is beginning to dilate. Even though you may not experience any contractions, you are now in the latent phase of early labor.
In the final month of pregnancy, your obstetrician or midwife may see you on a weekly basis to check the progression of your cervix's dilation. Between 1 and 3 centimeters dilation, you remain in the latent phase of labor. The heavy weight of your baby creates pressure on your cervix, slowly encouraging it to soften and widen and at this point, your baby's head may "settle" into your pelvis. You may hear this referred to as the "baby dropping."
Progression of Dilation
As the day of birth nears, you may begin to experience contractions as your body prepares for labor and delivery of your baby. With each contraction, a little bit of pressure stretches the cervix, encouraging it to further dilate. This stage of labor progresses differently for every woman but your doctor will likely admit you to the hospital when your cervix is at least 3 centimeters dilated. You may experience false labor that does not dilate the cervix and in this case, your doctor may send you home to wait a little longer.
Effects of Dilation
When your cervix reaches 4 centimeters of dilation, you enter the active phase of labor. Contractions become more intense as your uterus works to stretch open your cervix. The active phase of labor may last a couple of hours or longer and during this phase, your cervix will continue to dilate. Your obstetrician may now break your water if it has not already broken on its own. At 8 centimeters of dilation, you enter the transition phase of labor and contractions become very intense as birth nears.
When your cervix reaches 10 centimeters of dilation you will be taken to the delivery room. You may feel intense pressure and the urge to bear down at this point. Your doctor will instruct you in the proper method of pushing. The birth of your baby is now very close at hand.