Effacement and Dilation

How does effacement and dilation of the cervix occur?

The cervix, composed of strong muscles, is located at the neck of the uterus. Prior to pregnancy, the cervix is long, thick and completely closed. In addition, the cervix should stay this way until the third trimester, when it will begin to change as labor draws near.

The majority of healthcare providers begin routine cervical checks around the 37^th week of pregnancy. The healthcare provider will insert her gloved fingers into the woman’s vagina to assess cervical changes. While cervical examinations should not be painful, some women do feel uncomfortable, especially if contractions are taking place. During these checks, the cervix is examined for signs of dilation and effacement. In addition, your healthcare provider can determine which station your baby is currently in. Sound confusing? For most first time parents, it is. In this article, we will describe what your doctor is referring to during these cervical examinations.

Dilation refers to the opening and widening of the cervix, which will allow the baby to pass through during a vaginal delivery. Healthcare providers measure dilation in terms of centimeters, ranging from 0-10. Ten is fully dilated and ready to begin the pushing phase of labor. Early dilation of the cervix could lead to premature delivery, causing a multitude of complications in the baby, including breathing problems and jaundice.

Effacement refers to the shortening and thinning of the cervix. Healthcare providers describe effacement in terms of percentages, ranging from 0-100%. One hundred percent is completely thinned out and merged with the uterine wall.

Station refers to how far the baby’s head had settled into the mother’s pelvis. Healthcare providers measure station in terms of centimeters, ranging from -3 to +3. When the baby has not settled into the pelvis, negative numbers will be used to describe the positioning of the fetus. Once the baby has settled into the pelvis, but not into the birth canal, the station will be assessed as a 0. When the fetus begins descending into the birth canal, positive numbers are used. +3 describes the positioning when the baby’s head is at the perineum, just before delivery. As the baby progresses downward into the pelvis and then into the birth canal, most women feel increased pressure and pain in the vaginal area.

As labor progresses, healthcare providers will continue to monitor the progression of the cervix. Once the bag of water has broken and the risk of infection increases, most healthcare providers limit or avoid checking the cervix for changes. While some women may feel discouraged when cervical examinations reveal slow or absent progression, it can also be beneficial for women to know exactly how their bodies are responding to the demands of labor.

Comments: Effacement and Dilation

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2011miRacLe - 527 days ago.
I have been 70% effaced since last week wed. & no dilation @ all. I have another appt. tomorrow so hopefully I effaced & start to dilated soon, I want to see my bundle of joy already.. On 11/28/11 I was 50% effaced & when I went back on 11/30/11 I was 70%, I thought that was kind of quick. My doctor says that I effaced so quickly b/c I have been too much walking.

dreamgirl - 837 days ago.
Jlevine - I know it's been a while since you posted, but I'll answer anyway... Yes it is possible to go backwards. It happened to me when I was in induced with my 3rd child. The nurse checked me and said I was at 4. A couple hours later, she checked again, and said I was at 3. My husband was like 'What the...' He asked if it is possible to go backwards and the nurse said it does happen. Contractions work to open and close the cervix.

jlevine - 1052 days ago.
I have a question that maybe someone can answer for me! I am not Pregnant, but a friend of mine is. she is due in about 2 weeks. she went for a check last week and the dr. told her she was 1cm dilated. a fgew days later she went to the hospital because she thought she was in labor.. having contractions and whatnot. the Hospital told her she was 3cm dilated. well Today when she went back in to see her dr for her weekly visit her dr. told her that she was still 1cm!! how is that possible? is it possible to go backwards?

ann38 - 1119 days ago.
i am 1 cm and 50% affaced and my ? is how long after you start the affaced how long after that does labor start does anybody know