Today we’re chatting cervical exams. I get questions all the time about checking the cervix.
In regards to today’s discussion, we’re chatting the cervix in a pregnant woman, but some of the things discussed can be applied to non-pregnant women.
What is the purpose of checking a cervix?
A cervical exam is performed to assess the status of a woman’s cervix! It’s not particularly comfortable to have your cervix examined and there are very specific aspects of a cervical exam. During a cervical exam, the provider is assessing the location of your cervix, the dilation, the consistency, the effacement, and the station of the baby’s head – all at the same time. What the heck are all those things you ask? Let’s break it down.
Where is my cervix?
Your cervix is in the posterior vagina, however, a cervix can point different directions!
Providers clarify cervix position in a pregnant woman as: anterior, mid-position, or posterior. A common question I get is this: If my cervix is posterior, does that mean I won’t go into labor? Easy answer: Almost everyone has a posterior cervix at the end of your pregnancy! It’s not until active labor that the cervix starts to swing from back to front with labor contractions.
Also, did you know during your fertile time of your menstrual cycle, your cervix swings forward (or anteriorly) in anticipation of needing to be ready for sperm to enter (should there be any swimmers nearby). If you’re still wondering where you cervix is, it doesn’t hurt at all to reach back and feel it. Some fertility awareness methods do exactly that – they recommend the woman assess the position of her cervix to time intercourse appropriately. Okay, one more nugget…for my midwifery students that don’t know how to assess a cervix that isn’t dilated (also known as closed), I recommend they go home and feel their own cervix to learn what a non-dilated cervix feels like (this is also a good tip for labor and delivery nurses learning cervical exams). Okay, fun facts over…moving along!
What is cervical dilation?
There are all sorts of cervical dilation representations – just imagine a baby’s head is behind each of the circles and you’ve got the gist of what the provider is feeling through your cervix. Dilations is very subjective but most providers agree with the following depiction in the wooden circle. A cervix that’s about 5 centimeters dilated feels like a soda can top! Dilation tells your provider or nurse if you are in labor or the stage of labor you are in.
Your cervix has consistency!
Your cervix can be super soft, moderate or firm. I like to explain cervix consistency akin to avocados. The avocado that you can slice open and make guacamole from as soon as you get home from the grocery store is a soft cervix. The avocado that has to sit on the counter five days before you can make said guacamole is a firm cervix. The moderate cervix is somewhere between soft and firm. In labor, the softer cervix the better!
Your moveable, opening, consistent cervix has one more amazing aspect – effacement!
Effacement is the thinning of your cervix. Most women have a cervix that is approximately 4 to 5cm in length – this is referred to as “long” or 0% effaced”. During labor, the contractions push the baby’s head onto the cervix and cause the cells the thin and lengthen – providers call this action effacement. In the picture above, from left to right, you can see how the cervix in front of the baby’s head is slowly shortening, then stretching to the sides of the vagina. As the cervix stretches and things, the effacement improves to 100% – or almost as thin as a sheet of paper!
In the picture below from the Mayo Clinic, picture A demonstrates a cervix that is likely closed (no dilation, no effacement…or “closed” and “long”). In picture D, the cervix has opened and thinned out considerably (effacement), and you can see the baby’s amniotic sac “bulging” out of the cervix. Yes, the amniotic sac does sometimes feel like a water balloon – it’s a very surreal feeling.
In your first pregnancy, effacement takes a little bit of time. In subsequent pregnancies, your cervix is smart and can remember what it already did once before. So sometimes a mama in labor with her third baby will efface her cervix much faster than a mama with her first baby. This video shows effacement beautifully. It’s the video I show my group prenatal care mamas about what contractions do to your cervix during labor. And she has a British accent. WIN.
Lastly, where is the baby’s head in the pelvis?
This is known as station. Station is assessed by the provider palpating for the part of your pelvis called the ischial spines. The provider locates the spines and then assesses where the baby’s head is in location to bony prominence of the spine. Before labor starts, most babies are at a station of -4 or -3. During labor, as the contractions push the baby’s head toward the pelvic floor, the baby moves from the negative integers to the positive integers. Around 0 station, or when the baby’s head is at the level of the bony prominences, the mama usually starts to feel more pressure in her pelvis and vagina. Around +1 or +2 station, mamas can or do start pushing (once the cervix has effaced completely). And at +3, +4, +5, you will see a small crown, then a moderate crown, and finally a large crown of the baby’s head, respectively.
Let’s tie it all together with two examples of fictional, but Disney-inspired, mamas. These examples are to understand how the cervical exam is reported to a mama and what should be expected of the provider assessing the cervix:
Elsa is in the clinic at 40 weeks, 5 days pregnant and is considering a postdates induction of labor after 41 weeks. Else wants to see what her cervix is before scheduling an induction of labor. Midwife Jane examines her cervix and tells Elsa her cervix is: 2 centimeters dilated, 60% effaced, posterior, soft, and the baby is cephalic at -2 station.
Anna is on labor and delivery and was admitted for an induction of labor for gestational hypertension at 38 weeks, 2 days. Midwife Jane examines Anna’s cervix and tells Anna her cervix is: closed, 50% effaced, posterior, moderate and the baby is cephalic at -3 station.
A few other things particular to midwives and cervical exams…
There should always be a reason to check your cervix and someone should always have permission to do so.
Most providers will assess your cervix at your first OB visit and then again much closer to your due date. Within the past few decades, some inductions were offered to women between 37 to 39 weeks of pregnancy and many times a provider examined a cervix weekly in the office in order to schedule the induction of labor. Inductions without a medical reason are not recommended before 39 weeks, 0 days and weekly cervical checks at 36 weeks of pregnancy are slowly drifting to the wayside.
Some women don’t have their cervix checked until they show up in labor – and that is perfectly fine! I like to counsel that if your cervical exam (in the clinic or labor and delivery) isn’t going to change to recommended plan of care, then I don’t recommend doing the cervical exam.
That’s it for cervical exams. Hope this clarifies the mystery of cervical exams! If you haven’t yet, go find your cervix!
Happy hump day…
Jamie