Cervical cerclage (sir-vick-al kirk-ledge) is a procedure used to treat cervical incompetence. Research suggests that cervical cerclage reduces the risk of preterm delivery in women with proven cervical insufficiency. However, the timing of cervical cerclage may also affect the outcome.
An incompetent cervix occurs when the cervix becomes too weak to sustain the pressure of pregnancy. The cervix opens slightly, putting you at risk for preterm labor. Cervical incompetence is one of the most common causes of pregnancy loss in the second trimester.
A short cervix is one of the most significant risk factors for premature birth. It is recommended that all pregnant women have their cervical length measured between 14 and 28th weeks of pregnancy. If tests show that the mother’s cervix is short or insufficient, cervical cerclage placement should be performed. Cervical cerclage helps reinforce the cervical muscle and can help prevent preterm birth. During cervical cerclage placement, the cervix is stitched closed with strong sutures, which help the cervix remain closed under the weight of the baby, amniotic fluid and membrane. The placement of cerclage is an extremely effective treatment for the prevention of preterm birth, and this treatment has been in use for about 60 years.
Cerclage is a surgical procedure to help hold the cervix closed, delaying labor. Cerclage has helped some high-risk pregnancies last longer. The health care provider will use a speculum to open the vagina, access the cervix, and stitch it shut. This prevents early dilation and promotes full-term, positive pregnancy outcomes.
When is a Cervical Cerclage a Necessity?
Before pregnancy, the cervix is closed, long and firm. During pregnancy, the cervix gradually softens, decreases in length and opens (dilates) in preparation for birth. If you have an incompetent or short cervix, however, your cervix might begin to open too soon. As a result, you could experience pregnancy loss or give birth prematurely.
Your health care provider might recommend cervical cerclage during pregnancy to prevent premature birth if you have:
- History of second-trimester pregnancy loss related to painless cervical dilation in the absence of labor or placental abruption (history-indicated cervical cerclage)
- Prior cerclage due to painless cervical dilation in the second trimester
- Painless cervical dilation diagnosed during the second trimester
- A short cervical length (less than 25 millimeters) before 24 weeks of pregnancy, in a singleton pregnancy
A thorough exam of your cervix including a transvaginal ultrasound performed by a doctor who specializes in high-risk pregnancies is highly recommended.
Cervical cerclage has been a common practice in obstetrics since it was first described by Shirodker and then McDonald in the 1950s.
There are a few different ways to perform cerclage. All of them serve to tighten and strengthen the cervix, keeping it closed until the pregnancy is brought to term avoiding preterm birth. Your gynecologist may:
- Place stitches around the outside of the cervix.
- Make a small incision in the cervix, and then thread it through with surgical tape to close it.
- Transabdominal cerclage is when the surgeon ties surgical tape around the outside of the cervix, and hold it in place with stitches
Cervical cerclage is typically done as an outpatient procedure at a hospital or surgery center under regional or general anesthesia.
Amniotic Sac Protrusion
If cervical incompetence is not caught until later in the pregnancy, the amniotic sac may protrude through the cervix. This problem can be addressed in one of two ways:
- A catheter (narrow tube) with a small balloon is introduced into the cervix. The balloon is then inflated to support the amniotic sac.
- A catheter is inserted through the urethra to fill the bladder with liquid. The pressure from the bladder can then nudge the amniotic sac back through the cervix.
Once the amniotic sac is back in place, we can stitch up the cervix.
Removal of Cervical Cerclage
The cervical stitches must be taken out prior to the beginning of labor. This will not cause labor to start. However, if you go into labor early, with the stitches still in place, this is a medical emergency. They must be removed immediately. In some cases, the baby must be delivered via C-section.
Your doctor may recommend bed rest as part of your treatment.
As with any surgery, there are some risks to performing cervical cerclage. Cervical cerclage is not without risk. Reported adverse events shortly after suture insertion include abdominal pain, vaginal bleeding, premature prelabour rupture of the membranes and bladder injury. These risks are rare, and your medical team will take every precaution to ensure a safe procedure. Some risks include:
- Damage to the cervix
- Hemorrhaging (blood loss)
- Preterm labor
- Preterm premature rupture of membranes (pPROM) – this means the water breaks much too early
- Cervical stenosis (the cervix narrows or closes permanently)
- Tearing of the cervix or uterine tissue, upon entering labor with the stitches still in place
If you believe you are at risk for cervical incompetence, bring it up with your gynecologist as soon as you can. It’s better to catch this issue early on, so that steps can be taken to reinforce your cervix before the baby gets too big and before the amniotic sac is forced through. Early treatment with cerclage can significantly reduce your chances of pre-term labor and miscarriage.