Cervix Dilation Chart: Signs, Stages And Procedure To Check

Image: Shutterstock

CervixⁱXThe lowest portion of the uterus that connects to the vagina to form a passage between the two organs. dilation is the opening of the cervix, the neck of the uterus, during childbirth. Body changes during the labor process to allow the baby to pass through the birth canal. Although it is exciting to hold the baby, many women may be nervous and worry about the labor pain and delivery near the due date. Knowing these changes may help them to stay calm.

Childbirth includes three stages, and cervical dilation is crucial since it allows the baby to come out. Vaginal delivery may not be possible if there is no adequate cervical dilation during the labor. Doctors may also use various interventions to dilate the cervix if there is a delay. Read on to learn more about the signs, evaluation, and process of cervix dilation during labor.

What Is Cervix Dilation?

Image: Shutterstock

It is the opening of the neck of the uterus, which happens in the first stage of labor. The cervix dilates (uterus opens) due to contractions, and is a vital part of labor and delivery. The cervical dilation measurement is noted in centimeters. It starts from 1cm and grows to 10cm when it is called a complete dilation (1). Once the cervix is fully dilated, the baby can be delivered through the cervical opening.

If your due date is around the corner and your cervix is dilating, then it could mean you will soon get into labor. Typically, the cervix starts to dilate in the first phase of labor, which is also called the latent phase (1).

Dilation And Effacement: What Is The Difference?

Image: Shutterstock

The stretching and thinning of the cervix is called effacement. Cervical effacement is measured in percentage and mostly happens before dilation. The cervix thins and softens at first, and then opens. This happens when labor begins, which is usually around week 37. However, in some women, it could happen during week 38 or later.

Usually, in the first pregnancy, the cervix dilates during labor or after the contractions start. And in some cases, cervical effacement and dilation might happen just before the labor (2). As every pregnancy is different, the occurrence of effacement and dilation can differ.

How Do You Know If Your Cervix Is Dilating?

You will be able to notice even the slightest of changes in the body if you are observant as you near the due date. The following signs indicate that the cervix is dilating.

1. Lightning crotch: It is the sudden and intense pain experienced in your vagina when your baby descends. Some pregnant women say that the pain feels like a punch in the crotch. When you experience such pain near your due date, it could mean that your baby is positioning for delivery (3).

2. Uterine contractions: When contractions are frequent and painful, it is most probably a sign of approaching labor, effacement, and dilation (4). In this stage, cervical dilation and contractions cause the cervix to open from zero to three centimeters.

3. Ruptured membranes or breaking of water: This generally happens during the active phase of stage one labor. When a gush of water is released, the pressure might open the cervix.

Image: Shutterstock

4. Mucus plug discharge: Mucus plug works as a seal to your cervix, and protects your little one from bacteria. So when your cervix opens, the mucus plug comes out (5).

6. Bloody show: Brown or pink colored discharge could be a result of dilation. If you start noticing some stains, then it might mean your cervix has dilated (6).

Things to know

Cervix ripening is done when you have an overdue pregnancy or health complications such as preeclampsiaⁱXA pregnancy disorder characterized by high blood pressure, water retention, and protein content in urine. and gestational diabetesⁱXPregnancy-specific condition characterized by high blood sugar levels, which may pose a risk of complications. (13).

How Does Checking Cervix Dilation Help?

Image: Shutterstock

Checking cervical dilation helps you to know how close you are to labor and the effective management of labor. When your due date is nearing or has passed, your doctor may check the cervix to see if it is dilated.

Gretchen, a mom who was driven to the hospital in active labor and was 10 cm dilated when her midwife checked her first, shares her childbirth and labor experience. She says, “I have no idea how far along I am. I hear my midwife say she wants to check my dilation so I don’t wear myself out pushing too early.”

Her midwife checked and told her that she was 10 cm dilated. She adds, “I’m not sure what happened after that because another contraction rolls me back to my knees, and I hear my doula’s soft voice in my ear, ‘You’re there. All you have to do now is push your baby out (i).’” Checking cervical dilation in Gretchen’s case helped her midwife determine that she was fully dilated and ready for the pushing stage of labor.

Procedure To Check The Cervix For Dilation

Doctors usually do a cervical exam to check the dilation using their fingers. It is a sterile method that measures the dilation in centimeters (7) (8).

Steps to check cervix dilation: Follow these steps to check if the cervix is dilated.

i. Use two fingers: Index and middle fingers are inserted into the vagina and against the cervix to gauge the opening. Avoid the anal area.

ii. Assess the dilation: The two fingers should feel the cervix and the cervix opening to assess the cervical dilation and cervical length.

You can use the cervix dilation chart to understand the cervix dilation stages and compare your dilation.

Cervix Dilation Chart

The below chart has been taken from the US Operational Obstetrics and Gynecology (8).

Although professionals generally recommend checking cervical dilation before labor, there are certain cases where they do not suggest it.

When Not To Check Your Cervix During Pregnancy?

If your doctor finds it risky to check cervical dilation, then do not attempt it. Cervical dilation examination should only be done when your medical professional has recommended it. Otherwise, do not attempt it.

Next, we see if it is possible to dilate the cervix to speed up the labor process.

Are There Ways To Dilate The Cervix?

Image: Shutterstock

Yes, there are natural and medical ways to dilate the cervix. To dilate the cervix, it has to be softened (cervical ripening) first. Usually, medical experts prefer waiting for it to happen naturally. But in some cases, it becomes necessary to dilate the cervix and induce labor.

Some of the natural methods include walking, using a birthing ball, taking herbal supplements, indulging in sexual intercourse, and nipple stimulation. Medical methods include medications and medical/surgical procedures such as stripping of the membranes (9).

Things to know

Balloon or hygroscopic dilators with saline and prostaglandin infusions are often tried for dilating the cervix (13).

How Long Does Each Stage Of Labor Last?

The process of labor is typically divided into three stages (10).

1. First stage: In the first stage of labor, also called established labor, the cervix dilates up to about four centimeters, and the contractions become more regular and increase in intensity. If you have your first baby, this stage might last for about eight to 18 hours, whereas, in subsequent pregnancies, it might last for about five to 12 hours.
2. Second stage: In this stage, the cervix is fully dilated (to 10cm), and the womb muscles are actively contracting and relaxing, preparing for the final stage of pushing the baby out. Once the urge arises, it transitions into the active phase. This stage lasts about two to three hours, depending on the initiation of the active phase of the labor.
3. Third stage: The last and final stage of labor refers to the time when the baby has been delivered, but the mother has yet to release the placenta.

Infographic: What Are The Risks Of Cervical Ripening?

Cervical ripening is a process of softening and opening the cervix for childbirth. Nonpharmacologic methods, medications, and certain devices are used for cervical ripening. Read through the infographic to know the common risks of cervical ripening.

Illustration: Momjunction Design Team

Get the high-quality PDF version of this infographic.

Download Share

Was this article helpful?

The following two tabs change content below.

• Reviewer
• Author
• Editor
• Fact-checker

Dr. Sangeeta AgrawalFRCOG, MD, DNB, DGO

Dr. Sangeeta Agrawal is an obstetrician and gynecologist with around 29 years of experience in the field. She worked in Royal London, St. Bartholomew’s, North Middlesex, and Barnet General hospitals in London and currently runs her clinic in Mumbai. She is also attached to Bhatia Hospital, Breach Candy Hospital, Wockhardt Hospital, and Global Hospital. Her areas of expertise include obstetrics...more

Dr Bisny T. JosephMedical Doctor

Dr. Bisny T. Joseph is a Georgian Board-certified physician. She has completed her professional graduate degree as a medical doctor from Tbilisi State Medical University, Georgia. She has around 5 years of experience in various sectors of medical affairs as a physician, medical reviewer, medical writer, health coach, and Q&A expert. Her interest in digital medical education and patient education...more

Rebecca MalachiBSc

Rebecca is a pregnancy writer and editor with a passion for delivering research-based and engaging content in areas of fertility, pregnancy, birth, and post-pregnancy. She did her graduation in Biotechnology and Genetics from Loyola Academy, Osmania University and obtained a certification in ‘Nutrition and Lifestyle in Pregnancy’ from Ludwig Maximilian University of Munich (LMU). She has been into health and...more

Reshmi DasMSc

Reshmi Das has over four years of experience as a clinical coordinator, medical content writer and medical conference coordinator. Her continuous interest in medical journals and writing makes her write well-researched articles for MomJunction. She writes health and wellness articles for children and pregnant and lactating women. Reshmi has completed her post graduation in Biotechnology from MITS School of Biotechnology,...more