A cerclage is a stitch placed around the cervix during pregnancy to hold it closed and prevent premature birth or pregnancy loss. It’s used when the cervix opens too early, a condition called cervical insufficiency, which typically causes no pain or warning signs before the cervix begins to dilate. The procedure is one of the most effective interventions for this problem, with studies showing live birth rates jumping from 23% to 86% in women who received a cerclage after previous losses.
Why a Cerclage Is Needed
The cervix normally stays firm and closed until late in pregnancy, then gradually softens and opens as labor approaches. In some women, the cervix weakens and opens far too early, sometimes in the second trimester, without contractions or any noticeable symptoms. This can lead to pregnancy loss or extremely premature delivery.
Your doctor may recommend a cerclage if you have a history of painless cervical dilation and second-trimester delivery in a previous pregnancy, or if monitoring reveals your cervix is shortening or opening before 24 weeks. Monitoring usually involves ultrasounds every two weeks from week 16 through week 24. If your cervix shortens below a certain threshold during that window, a cerclage becomes an option. For women with a short cervix but no prior preterm births, vaginal progesterone alone may be sufficient.
Types of Cerclage
McDonald Cerclage
This is the simpler and more common approach. A suture is stitched around the outside of the cervix in a purse-string pattern (like a drawstring bag) and tied at the front. It requires no cutting into the tissue surrounding the cervix, which makes it faster to place and easier to remove later.
Shirodkar Cerclage
This technique is more involved. Small incisions are made in the vaginal tissue at the front and back of the cervix, allowing the surgeon to place a band of woven tape deeper into the tissue, closer to the internal opening. The tape is threaded through tunnels on both sides of the cervix and knotted at the back. The incisions are then closed, and in some cases the tape is buried entirely beneath the surface to reduce infection risk. Because the stitch sits higher and deeper, it can provide a stronger closure in certain situations.
Transabdominal Cerclage
When a vaginal cerclage has failed in a previous pregnancy, or when the cervix is extremely short, scarred, or structurally abnormal, the stitch can be placed through the abdomen instead. This is typically done laparoscopically (through small incisions in the belly) and requires general anesthesia. Unlike vaginal cerclages, an abdominal cerclage stays in place permanently and requires delivery by cesarean birth. It can even be left in between pregnancies.
When It’s Done
Timing depends on the reason for the cerclage. A planned (prophylactic) cerclage, placed because of a known history of cervical insufficiency, is usually done between 12 and 14 weeks of pregnancy. An ultrasound-indicated cerclage, triggered by cervical shortening found during monitoring, happens sometime between 16 and 24 weeks. Emergency cerclage, performed when the cervix has already dilated and membranes may be bulging through, can be placed up to 24 weeks but carries higher risks the longer it’s delayed.
Delaying the procedure into the later second trimester increases the risk of infection inside the uterus by about 2.6 times and triples the chance of the membranes rupturing before 32 weeks.
What to Expect During the Procedure
A transvaginal cerclage is typically performed in a hospital but does not require an overnight stay. Most women go home the same day. Spinal anesthesia is the preferred option for vaginal cerclage because it provides reliable numbness while avoiding the risks of general anesthesia during pregnancy, including airway complications and aspiration. Your anesthesia choice will depend on your gestational age, whether the uterus needs to be relaxed, and your own preference.
For a transabdominal cerclage done laparoscopically, general anesthesia is required.
Recovery After Placement
Because cerclage is a same-day procedure, recovery is relatively quick. You can expect some mild cramping and light spotting for a few days. Your doctor will likely recommend pelvic rest, meaning nothing placed in the vagina and no sexual intercourse, for a period after the procedure.
There’s a common assumption that strict bed rest is necessary after a cerclage, but the Society for Maternal-Fetal Medicine actually recommends against routine activity restriction for women at risk of preterm birth, including those with a cerclage. Prolonged bed rest carries its own risks, including blood clots and muscle loss. Your provider may give you individualized guidance, but blanket bed rest is no longer standard practice.
How Well It Works
For planned cerclage in women with a history of cervical insufficiency, outcomes are strong. In one study of women who had previously lost pregnancies or delivered extremely early, the rate of delivery beyond 32 weeks went from 13% before cerclage to 81% after, with the median delivery shifting from 21 weeks to 37 weeks, which is essentially full term.
Emergency cerclage, while more challenging, also shows meaningful success. A study of 158 emergency cases found a live birth rate of 82%. However, outcomes depend heavily on how dilated the cervix already is. When dilation was less than 3 centimeters, the neonatal survival rate was about 90%. When dilation was 3 centimeters or more, survival dropped to around 75%.
Risks and Complications
The most significant risks of cerclage are infection and premature rupture of membranes. The stitch introduces a foreign material into the cervix, which creates a potential pathway for bacteria. This risk grows substantially when the cerclage is placed later in pregnancy or in emergency situations.
Emergency cerclage carries additional challenges because the surgeon is working with an already-open cervix and potentially bulging membranes. The membranes can rupture during the operation itself. In a large study of emergency cases, serious maternal complications were rare: cervical lacerations occurred in about 1.25% of women, and deep vein thrombosis (blood clots in the legs) developed in another 1.25%, likely related to the combination of pregnancy’s natural clotting tendency and reduced activity afterward.
Cerclage Removal
A transvaginal cerclage is typically removed around 37 weeks of pregnancy, once the baby has reached a safe gestational age. Removal of a McDonald cerclage is straightforward and can often be done during a regular office visit without anesthesia, since it involves simply cutting and pulling the exposed suture. A Shirodkar cerclage may require a bit more effort if the tape was buried beneath the tissue, but it is still usually removed in an outpatient setting.
A transabdominal cerclage is not removed before delivery. Because the stitch sits deep inside the abdomen, delivery must happen by cesarean. The stitch can be left in place for future pregnancies, which avoids the need for a second surgical placement.