Short cervix: early signs and what cerclage involves

What is cervical insufficiency?

Cervical insufficiency (also called an incompetent cervix) is when your cervix opens without pain during the second or early third trimester. This happens because of a problem with how it's built or how it works. This happens without contractions, according to StatPearls. That's what makes it so different from typical preterm labor. There's no contracting uterus pushing things along. It's just a cervix that isn't staying closed the way it needs to.

It's also not common. Cleveland Clinic estimates it happens in about 1 in 100 pregnancies. That low number is part of why it can feel like a confusing diagnosis. Most pregnant people have never heard the term before it applies to them.

Why is it so easy to miss?

Unlike other signs of premature labor, like regular contractions or your water breaking, cervical insufficiency often causes no noticeable symptoms at all, per Cleveland Clinic. Doctors call this asymptomatic (without symptoms). By definition, it either causes no symptoms, or only mild, nonspecific (not clearly pointing to one cause) symptoms, according to StatPearls. That matters. The signs it does cause can easily be mistaken for ordinary late-pregnancy discomfort. That's why your provider relies so heavily on your history and screening. Symptoms alone are not enough.

What are the warning signs?

When cervical insufficiency does cause symptoms, they tend to be subtle, not dramatic. Still, it's worth knowing them by name so you don't dismiss them. According to StatPearls and Cleveland Clinic, the signs to watch for include: - Pressure or pain in your pelvis or belly - Backache - More vaginal discharge, or a change in it - Vaginal spotting or bleeding

Cleveland Clinic advises calling your pregnancy care provider if you notice any signs of miscarriage. These include bleeding, pelvic pain, or contractions. None of these symptoms alone confirms cervical insufficiency. But because the condition is so often silent, any of them is a good, low-stakes reason to call rather than wait.

What causes it?

The most common cause that develops over time is cervical trauma (injury to the cervix), according to StatPearls. This can come from tears during a previous childbirth. This is especially true of a precipitous (very fast) birth or a long second stage of labor. It can also come from procedures like cervical conization or a LEEP (a procedure that removes abnormal cervical tissue). In other cases, the cause is a structural or functional problem with the cervix you were born with, rather than an injury or procedure.

How do doctors diagnose it?

Because there often aren't clear symptoms to go on, diagnosis often relies on your pregnancy history. A history-based diagnosis generally needs a pattern. This means at least 1 to 3 second-trimester losses in a row, or early preterm births, linked to painless cervical opening. StatPearls notes the exact number required varies by medical group. This is one reason your provider will ask detailed questions about any past pregnancies, even ones that feel long ago or hard to talk about.

What happens with a cerclage?

If your provider recommends a cerclage, it's a procedure that stitches the cervix shut to help prevent premature labor. Per Cleveland Clinic, it typically happens around 12 to 14 weeks of pregnancy. The stitches are usually removed around 37 weeks so you can have a vaginal delivery.

Once a cerclage is in place, StatPearls advises seeking evaluation if you develop any of the following: fever, belly pain, cramping, contractions, fluid loss, or vaginal bleeding. Keep this list somewhere easy to find, like a note on your phone or a magnet on the fridge. It can take the guesswork out of a moment when you might otherwise second-guess whether something is worth calling about.

Frequently asked questions

Sources

1. Cervical insufficiency is a condition where the cervix painlessly dilates during the second or early third trimester due to a functional or structural defect, without associated uterine contractions. — StatPearls (NCBI Bookshelf)
2. Cervical insufficiency is by definition either asymptomatic or produces only mild, nonspecific symptoms, including pelvic pressure, backache, an increase in vaginal discharge, or vaginal spotting. — StatPearls (NCBI Bookshelf)
3. A history-based diagnosis of cervical insufficiency generally requires a history of at least 1 to 3 consecutive second-trimester pregnancy losses or early preterm births linked to painless cervical dilation (the exact number required varies by medical organization). — StatPearls (NCBI Bookshelf)
4. The most common acquired cause of cervical insufficiency is cervical trauma, which can result from cervical lacerations during childbirth (especially precipitous birth or a prolonged second stage of labor), cervical conization, or LEEP procedures. — StatPearls (NCBI Bookshelf)
5. Once a cervical cerclage is in place, patients should be told to seek evaluation if they develop fever, abdominal pain, cramping, contractions, loss of fluid, or vaginal bleeding. — StatPearls (NCBI Bookshelf)
6. Incompetent cervix (cervical insufficiency) occurs in about 1 in 100 pregnancies. — Cleveland Clinic
7. Unlike other signs of premature labor such as contractions or the water breaking, cervical insufficiency often causes no noticeable symptoms, and when signs do occur they can include pelvic pressure or pain in the belly, or spotting or changes in vaginal discharge. — Cleveland Clinic
8. A person should contact their pregnancy care provider if they experience signs of miscarriage during pregnancy, including bleeding, pelvic pain, and contractions. — Cleveland Clinic
9. Cervical cerclage (a procedure that sews the cervix shut to help prevent premature labor) typically happens around 12 to 14 weeks of pregnancy, and the stitches are usually removed around 37 weeks of pregnancy so a vaginal delivery can occur. — Cleveland Clinic