What is Cervix Effacement?

When we consider cervix effacement, we are looking not at the way the cervix opens, or dilates, but the process by which it thins out.

To give you a real-life example, picture a full roll of paper towels. As labor progresses, the cervix thins out, just like a roll of paper towels as they are discarded. When fully thinned, it would resemble the empty paper towel roll. Not a glamorous example, but you get the point.

So how does it signal that labor is approaching?

What many new moms don't realize is that after complete effacement, labor is soon coming. It is a better predictor than dilation. This process can take much longer than dilation itself, so the higher the percentage, the more thinning has occurred.

How is it measured?

Effacement in pregnancy is measured on a percentage basis from 0 to 100 with 0% meaning no thinning and 100% considered complete.