If you think you’re in labor, call your practitioner. When a practitioner is trying to determine whether you’re in labor, he performs an internal exam to look for several things:
Dilation: Your cervix is closed for most of your pregnancy but may gradually start to dilate during the last couple of weeks, especially if you’ve had a baby before. After active labor begins, the rate of cervical dilation speeds up, and the cervix dilates to 10 centimeters by the end of the first stage of labor.
Often, you’re considered to be in active labor when your cervix is about 4 centimeters dilated or 100 percent effaced.
Effacement:Effacement is a thinning out or shortening of the cervix, which happens during labor. Your cervix goes from being thick (uneffaced) to 100 percent effaced.
Credit: Kathryn Born, MAStation: When you’re in labor, the practitioner uses the term station to describe how far your baby’s head (or other presenting part) has descended in the birth canal in relation to the ischial spines, a bony landmark in your pelvis.
Position: When labor begins, the baby typically starts out facing to the left or right side. As labor progresses, he rotates until the head assumes a facedown position so that the baby comes out looking at the floor. Occasionally, the baby rotates to the opposite position and comes out sunny-side up, looking at the ceiling.