The cervix is a critical component to a healthy pregnancy. It connects the uterus (where your baby lives until birth) to the vaginal canal (the "exit route" for a non-cesarean birth), and essentially serves as the gatekeeper to your baby.

 

When all functions as intended, the cervix holds baby in until it's time for birth, and keeps potentially harmful germs/infection out. And when it's "go time" the superhero cervix will perform seemingly impossible feats of strength and flexibility (that's the "10 centimeters dilated!" we hear so much about during birth!) to send baby on their merry way.

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Outside of pregnancy, the cervix is closed and firm, but as pregnancy progresses, it gradually gets softer, decreases from about 1.5 inches in length to paper-thin (this is called effacement) and opens (or dilates) to 10 cm during birth.

 

Where problems can occur is if these changes start happening too soon. As explained in the introduction, there are many different (sometimes antiquated and just plain rude!) names for this phenomenon, the most popular of which is Incompetent Cervix (or IC for short). From here on out, we'll refer to it as IC or early cervical dilation.

 

So what happens if your cervix dilates too early? Research shows that there is a direct correlation between the length of the cervix and your risk of preterm birth - meaning the shorter your cervix is, the more likely you are to go into labor early.

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Why? The sad truth is that we just don't know. (Literally! Our friends at The Iris Fund founded an entire charity *just* to answer the very basic question of what causes a pregnant body to go into labor - and they're doing some very cool science to find out!)

Not every case of IC is symptomatic (beyond observation on ultrasound), but for some pregnant people, some potential signs of early cervical dilation can develop starting between 14 to 20 weeks of pregnancy, including:

• A sensation of pelvic pressure or "tugging"

• A backache that you've never had before

• Mild abdominal cramps or discomfort

• A change in vaginal discharge

• Light vaginal bleeding or spotting

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Unfortunately, many of these symptoms overlap with what would be considered "normal" pregnancy discomforts, and as a result, they are often overlooked by pregnant patients or dismissed by their providers.

 

As always in pregnancy, it's critical to #KnowYourNormal. Remember: no one knows your body better than you. If you notice any changes or concerning symptoms, you should trust your gut and #AlwaysAsk.

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How is IC diagnosed?

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The good news is that early cervical dilation can be seen on ultrasound.

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Transvaginal ultrasound imaging can be used to measure the length and dilation of your cervix. If your cervix is considered "short" (typically less than 25 mm, or ~1 inch, though some doctors use different standards) or shows signs of "funneling" those are red flags that there may be something awry. In that case, you should have further testing and monitoring.

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Sometimes a provider will recommend a pelvic exam to feel for dilation and effacement, but an ultrasound can typically detect early warning signs sooner than manual examination.

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Will I be screened for IC?

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It's important to note that checking for a short cervix or other signs of IC is NOT currently a standard of routine prenatal care. Your provider likely is not checking your cervical length unless you have other signs of preterm labor, a history of premature birth, or other risk factors.

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There is some emerging evidence that routine cervical screening could be beneficial even in low-risk pregnancies, but at this point in time, it's something you need to know about and ask for (see: Advocating for Yourself). No later than 16-18 weeks is the recommended time for the screening if you decide to request it.

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What are the treatment options?

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If you are at risk for early cervical dilation, there are several potential treatment options that you should discuss with your healthcare provider to determine what's right for you and your pregnancy. These may include:

• A cerclage (or "cervical stitch") - note that cerclages have been shown to be effective but there are various different types of cerclages with different recommended uses; we highly suggest speaking to a specialist with deep knowledge of IC & cerclage options, as an incorrectly performed cerclage can be dangerous to the pregnant person

• Progesterone supplements

• Bed rest (though there is little evidence that this is actually effective in improving outcomes)

• Use of a pessary has shown some effectiveness in certain scenarios (especially later in pregnancy)

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As always in pregnancy, having open lines of communication with your healthcare provider is key if you have been diagnosed with IC. Be sure to ask questions (here's a list!) to understand what to look out for and don't hesitate to get a second opinion as some providers are more familiar with treating early cervical dilation than others.

Early cervical dilation is considered a "rare" outcome, affecting an estimated 1 in 100 pregnancies - but like just stillbirth, even at only 1% that's still a lot of pregnancies! And every single one of those babies matter. So we feel strongly you deserve to be informed about IC.

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The scary part about IC is that more than half of cases occur in pregnancies without previous risk factors. So (again, just like with stillbirth!) even if you don't have any of the risk factors doesn't mean you're in the "safe zone."

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That being said, some factors which might put you at higher risk for IC include:

• Past history of preterm birth. Your risk of having another preterm birth doubles for every one you've had in the past. IC may not be the cause, but it's certainly worth looking into if you have a history of preterm birth, early stillbirth (20-24 weeks) or late miscarriage (14-19 weeks)

• Cervical trauma. This could include surgical procedures to treat cervical abnormalities, past D&C, or a cervical tear or injury during a previous birth (especially if you had an emergency c-section)

• Race. Like many adverse pregnancy outcomes, Black women seem to have a higher risk of developing cervical insufficiency. There isn't currently clear evidence to explain why, but we have a hunch...

• Certain conditions. This could include congenital conditions such as uterine abnormalities or disorders affecting your body's connective tissues such as Ehlers-Danlos Syndromes and Marfan Syndrome

• DES (grand)daughters. If your mother (or possibly even grandmother) took a commonly prescribed drug called diethylstilbestrol (DES) during pregnancy, you could be at higher risk of several health conditions, including cancers and certain "anatomical irregularities" of your reproductive organs, which could result in IC

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But remember: the most important thing is to trust your gut if something feels off. Never hesitate to ask questions, and if you aren't being heard, #UseYourMomVoice! Your concerns should always be taken seriously, especially when it comes to something as dangerous and unpredictable as IC.