Cervical effacement and dilation

Cervical effacement and dilation

During the first stage of labor, the cervix opens. The medical term for this is dilation. The cervix also thins out. The medical term for this is effacement. Dilation and effacement usually happen together. This process allows the baby to move into the birth canal. In figures A and B, the cervix is tightly closed. In figure C, the cervix is 60% effaced and 1 to 2 cm dilated. In figure D, the cervix is 90% effaced and 4 to 5 cm dilated. The cervix must be 100% effaced and 10 cm dilated before a vaginal delivery.

From Mayo Clinic to your inbox

Sign up for free and stay up to date on research advancements, health tips, current health topics, and expertise on managing health. Click here for an email preview.

We use the data you provide to deliver you the content you requested. To provide you with the most relevant and helpful information, we may combine your email and website data with other information we have about you. If you are a Mayo Clinic patient, we will only use your protected health information as outlined in our Notice of Privacy Practices. You may opt out of email communications at any time by clicking on the unsubscribe link in the email.