The Myth of a Vaginal Exam at the End of Pregnancy

Why It Might Not Be What You Think

Woman getting a vaginal exam and comfort from her partner
Photo © Science Photo Library/Getty Images

Vaginal exams. I don't know a single woman who likes them.

However, there is a myth perpetuated in our society that vaginal exams at the end of pregnancy are beneficial. The common belief is that by doing a vaginal exam one can tell that labor will begin soon. This is not the case.

Most practitioners will do an initial vaginal exam at the beginning of pregnancy to do a pap smear and other tests. Then they don't do any until about the 35-37 week mark unless complications arise that call for further testing or to assess the cervix.

Typically they will also test for Group B Strep at this point. If your practitioner wants to do a vaginal exam at every visit, you should probably question them as to why and for what benefit.

What a Vaginal Exam Measures

Vaginal exams can measure certain things:

  • Dilation: How far the cervix has opened. 10 centimeters being the widest.
  • Ripeness: The consistency of the cervix. It starts out being firm like the tip of your nose, softening to what your ear lobe feels like and eventually feeling like the inside of your cheek.
  • Effacement: This is how thin the cervix is. If you think of the cervix as funnel-like and measuring about 2 inches, you will see that 50% effaced means that your cervix is now about 1 inch in length. As the cervix softens and dilates the length decreases as well.
  • Station: This is the position of the baby in relation to your pelvis, measured in pluses and minuses. A baby who is at 0 station is said to be engaged while a baby in the negative numbers is said to be floating. The positive numbers are the way out!
  • Position of the baby: By feeling the suture lines on the skull of the baby, where the four plates of bone haven't fused yet, one can tell you which direction the baby is facing because the anterior and posterior fontanels (soft spots) are shaped differently. (This is not used in the office because it is difficult to tell with minimal dilation and intact membranes.)
  • Position of the cervix: The cervix will move from being a more posterior cervix to an anterior cervix. Many women can tell when the cervix begins to move around because when a vaginal exam is performed it no longer feels like the cervix is located near her tonsils.

What a Vaginal Exam Cannot Measure

What this equation leaves to be desired is something that is not always tangible. Many people try to use the information that is gathered from a vaginal exam to predict things like when labor will begin or if the baby will fit through the pelvis. A vaginal exam simply cannot measure these things.

Labor is not simply about a cervix that has dilated, softened or anything else. A woman's cervix can be very dilated and not have her baby before her due date or even near her due date. I've personally had women who had a cervix that was 6 centimeters dilated for weeks. Then there is the sad woman who calls me to say that the cervix is high and tight, she's been told that this baby isn't coming for awhile, only to be at her side as she gives birth within 24 hours.

Vaginal exams are just not good predictors of when labor will start.

Using a vaginal exam to predict advisability for a vaginal birth is usually not very accurate, for several reasons. First of all it leaves out the factor of labor and positioning. During labor, it's natural for the baby's head to mold and the mother's pelvis to move. If done in early pregnancy it also removes the knowledge of what hormones like Relaxin will do to help make the pelvis, a moveable structure, be flexible. The only real exception to this is in the case of a very oddly structured pelvis. For example, a mother who was in a car accident and suffered a shattered pelvis or someone who might have a specific bone problem, which is more commonly seen where there is improper nutrition during the growing years.

During labor vaginal exams can't tell you exactly how close you are either, so keeping them to a minimum then is also a good idea, particularly if your membranes have ruptured.

Okay, so there's not really a great reason to have a vaginal in exam done routinely for most women. So are there any reasons not to have vaginal exams? There sure are.

Vaginal exams can increase the risks of infection, even when done carefully and with sterile gloves, etc. It pushes the normal bacteria found in the vagina upwards towards the cervix. There is also increased risk of rupturing the membranes. Some practitioners routinely do what is called stripping the membranes, which simply separates the bag of waters from the cervix. The thought behind this is that it will stimulate the production of prostaglandins to help labor begin and irritate the cervix causing it to contract. This has not been shown to be effective for everyone and does have the aforementioned risks.

In the end, only you and your practitioner can decide what is right for your care in pregnancy. Some women refuse vaginal exams altogether, so request to have them done only after 40 weeks, or every other week or whatever she feels comfortable with.


Bergstrom L, Roberts J, Skillman L, Seidel J. "You'll feel me touching you Sweetie": Vaginal examinations in the second stage of labour. Birth 1992;19(1):10-8.

Downe S, Gyte GML, Dahlen HG, Singata M. Routine vaginal examinations for assessing progress of labour to improve outcomes for women and babies at term. Cochrane Database of Systematic Reviews 2013, Issue 7. Art. No.: CD010088. DOI: 10.1002/14651858.CD010088.pub2

Huhn KA, Brost BC. Accuracy of simulated cervical dilation and effacement measurements among practitioners. American Journal of Obstetrics and Gynecology 2004;191(5):1797-9.

Lenahan, JP Jr., Relationship of antepartum pelvic examinations to premature rupture of the membranes. Journal Obstetrics Gynecology 1984, Jan:63(1):33-37.

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