The process by which the cervix thins and shortens in preparation for childbirth.
What is Cervical Effacement?
Throughout pregnancy, your cervix is a long, thick, and firm 'plug' that keeps the baby safely inside the uterus. As you approach labor, the cervix must undergo two major changes: Effacement (thinning) and Dilation (opening).
Effacement is measured in percentages. A cervix that hasn't begun to thin is 0% effaced, while a 'paper-thin' cervix is 100% effaced.
How Effacement Happens
Effacement is caused by the baby's head dropping lower into the pelvis and pressing against the cervix. This pressure, combined with the release of prostaglandins (hormones that soften tissue), causes the cervix to shorten and literally pull up into the lower part of the uterus.
- First-Time Moms: Often experience effacement before dilation begins.
- Experienced Moms: Often experience effacement and dilation at the same time.
How is it Checked?
During late-pregnancy prenatal visits, your doctor or midwife may perform a cervical check. They will use their fingers to feel how much of the original 3–4 centimeter length remains.
The Bottom Line
Effacement is a sign that the 'doorway' is getting ready to open. While it can take days or even weeks to go from 50% to 100%, it is a clear indicator that your body is moving in the right direction!
Medical Disclaimer: All content in this section is for educational and informational purposes only and is NOT intended as medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Bloom is not a replacement for professional medical consultation and should not be used as a primary form of birth control. Read our full Terms of Service.
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