What is the Difference Between Dilated and Effaced

The main difference between dilated and effaced cervix is that dilated cervix is the opened cervix whereas effaced cervix is stretched and thinner. Furthermore, dilation follows effacement while the mucus plug passes out as a result of the effacement. 

Dilated and effaced are two stages of the cervix, which occur near labor. Also, both events prepare the cervix to pass the baby through the birth canal or vagina. 

Key Areas Covered 

1. What is Dilated
     – Definition, Process, Importance
2. What is Effaced
     – Definition, Process, Importance
3. What are the Similarities Between Dilated and Effaced
     – Outline of Common Features
4. What is the Difference Between Dilated and Effaced
     – Comparison of Key Differences

Key Terms 

Cervix, Child Birth, Dilated, Effaced, Labor, Uterus

Difference Between Dilated and Effaced - Comparison Summary

What is Dilated 

The dilated cervix is the cervix that opens as labour approaches. Generally, the cervix is the opening of the uterus. Further, dilation may occur during childbirth, miscarriage, as well as, in induced abortions. In childbirth, the cervix opens up to 1-3cm during the late pregnancy stages. Moreover, the repeating uterine contractions result in further dilation of the cervix up to 6 cm.

Dilated vs Effaced

Figure 1: Cervix Dilation Model

After that, the dilation becomes complete due to the pressure from the head or bottom of the child. Basically, the complete dilation of the cervix is around 10 cm. 

What is Effaced 

The effaced cervix is the thinning of the cervix as labor nears. Moreover, it accompanies with the cervix dilation. Generally, prior to effacement, the cervix has a long bottleneck shape in 4 cm long.  Throughout the pregnancy, it is tightly closed. Additionally, a plug of mucus protects the entrance; however, with the effacement of the cervix, this mucus plug loosens and passes out of the vagina. sometimes, this mucus contains blood as well.

What is the Difference Between Dilated and Effaced

Figure 2: Cervix

On the other hand, with the effacement, the cervix decreases its length and becomes a part of the lower part of the uterine wall. Furthermore, doctors measure the state of effacement as a percentage and the complete effacement is when the cervix stretches 100%. 

Similarities Between Dilated and Effaced  

  • Dilated and effaced are two stages of the cervix. 
  • They occur as labor nears. 
  • Moreover, they are important for the passage of the child through the vagina. 
  • Both are gradual processes. 
  • Their timing differs in women; some may take weeks or month while some may take overnight. 

Difference Between Dilated and Effaced 


Dilated refers to the opening of the cervix, while effaced cervix refers to the stretched and thinning of the cervix. 

Measured by 

Moreover, dilation is measured by centimeters while the effacement is measured by percentage. 

At the Vaginal Delivery 

The complete cervix dilation is 10 cm while the complete cervix effacement is 100% at the vaginal delivery. 


Dilated is the stage of the cervix near the labor. Also, it is measured by centimeters. Additionally, the complete cervix dilation is around 10 cm at the vaginal delivery. On the other hand, effaced refers to the stretched and thinned of the cervix. However, the measuring of effacement is by means of a percentage. Moreover, at the vaginal delivery, the complete cervix effacement is 100%. Therefore, the main difference between dilated and effaced is the effect of each process on the cervix. 


1. “Cervical Effacement and Dilatation.” Cervical Effacement and Dilatation | CS Mott Children’s Hospital | Michigan Medicine, Available Here.

Image Courtesy:

1. “Cervix / cervical dilation model, used to demonstrate dilation stages during ante natal class” By Matt Burton (CC BY 2.0) via Flickr
2. “Image from page 625 of “The practice of obstetrics, designed for the use of students and practitioners of medicine” (1910)” By Internet Archive Book Images via Flickr

About the Author: Lakna

Lakna, a graduate in Molecular Biology and Biochemistry, is a Molecular Biologist and has a broad and keen interest in the discovery of nature related things. She has a keen interest in writing articles regarding science.

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