Today, I was thinking about birth, and I suddenly thought to myself, "Women's bodies are all different. Yet, during labor, they always focus on your cervix getting to 10 cm dilated. How can *everyone* dilate to exactly 10 cm?!??"

So I googled it. And I found this post:

http://www.birthologie.com/birth/what-you-dont-know-about-your-cervix/

Now, I don't know for sure if I believe everything in this article, but I appreciated one of the comments posted:

"No, not all women dilate to “10″. When a care provider is checking a cervix in early labor, they are feeling for how big the opening is. Later in labor, after about 5 cm, the are checking for how much is left. So if there is 2 cm of cervix left, you are at 8cm. So 10cm just means the cervix is completely gone, not that it’s dilated to exactly 10 cm."

AHA! So that explains it.