Cerclage; a stitch placed in the cervix to help it stay closed during pregnancy; is recommended in specific clinical situations and not in others. The evidence varies significantly depending on why it is being considered. This guide helps patients with a history of cervical insufficiency, a short cervix found on ultrasound, or a dilated cervix found on exam understand what the evidence shows for their specific situation, what their options involve, and what questions to bring to their care team. Informed by ACOG Practice Bulletin No. 142 and SMFM Consult Series #65 and #70.
Your cervix is part of the conversation. Here is what the evidence shows.
Cerclage; a stitch placed in the cervix during pregnancy; is one of the more nuanced decisions in obstetric medicine. Whether it is right for you depends heavily on why it is being considered. The evidence is strong in some situations and limited in others. This guide will not tell you what to decide. It will give you an honest account of what the research shows for your specific situation and a question list to bring to your appointment.
This takes about 10 to 15 minutes. At the end you will have a printable question list tailored to your situation. Nothing is stored or transmitted.
Not a substitute for clinical care. Evidence: ACOG Practice Bulletin No. 142 (2014); SMFM Consult Series #65 (2023); SMFM Consult Series #70 (2024).
Step 1 of 4 · Your Situation
Tell me a little about why cerclage is being discussed.
The reason cerclage is being considered changes what the evidence shows and what the right questions are. Answer as best you can; you can skip anything you are unsure about.
Why is cerclage being discussed for you?
Is this a singleton pregnancy (one baby)?
Have you had a prior spontaneous preterm birth before 34 weeks?
Have you had a prior cerclage placed?
Have you had prior cervical surgery? (LEEP, cone biopsy, trachelectomy)
How are you feeling emotionally right now as you work through this?
Step 2 of 4 · Evidence and Options
What the evidence shows for your situation.
Select any options you want to explore. Expand any card for detail. Tap highlighted terms for definitions.
Step 3 of 4 · What Matters
Clarifying what feels most important to you.
These questions shape your personalized question list. There are no right answers.
Step 4 of 4 · Your Questions
Questions to bring to your care team.
Generated from your situation, selected options, and what matters most to you. Add your own below.
Your own questions
What else do you need to know? These will appear on your printed list.
Support beyond the decision
Navigating a complex pregnancy is one of the most emotionally demanding experiences a person can go through. If you are struggling beyond the decision itself; with fear, grief, isolation, or weight that feels unmanageable; support is available.
Postpartum Support International:postpartum.net; helpline, provider directory, pregnancy and loss support
National Maternal Mental Health Hotline: 1-833-943-5746: 24/7, free, confidential
The inability of the cervix to remain closed and support a pregnancy through the second trimester, in the absence of contractions or labor. Also called cervical incompetence. The diagnosis is primarily based on history; painless cervical dilation leading to second-trimester loss is the classic presentation.
Cerclage
A surgical stitch placed around the cervix to help keep it closed during pregnancy. Most commonly placed transvaginally (through the vagina). In certain cases a transabdominal approach (through the abdomen) is used. Usually placed between 12 and 16 weeks for history-indicated cerclage, and earlier for transabdominal.
Transvaginal cerclage (TVC)
The most common type of cerclage, placed through the vagina. Two main techniques: McDonald (a purse-string suture near the top of the cervix, easily removable) and Shirodkar (placed higher, often left in place). Both have similar outcomes in most studies.
Transabdominal cerclage (TAC)
A cerclage placed through the abdomen, either by open surgery or laparoscopy. Placed at the level of the internal os. Requires cesarean delivery. Used when transvaginal cerclage is not possible or has failed. SMFM recommends TAC for patients with a prior transvaginal cerclage who subsequently delivered before 28 weeks.
Cervical length (CL)
The length of the cervix measured by transvaginal ultrasound. A short cervix is generally defined as under 25mm in the mid-trimester (16 to 24 weeks). The shorter the cervix, the higher the risk of preterm birth; the relationship is continuous, not a sharp threshold.
History-indicated cerclage
Cerclage placed based on obstetric history; typically prior second-trimester losses or preterm births attributed to cervical insufficiency; without waiting for cervical change in the current pregnancy. Usually placed at 12 to 16 weeks.
Ultrasound-indicated cerclage
Cerclage placed in response to a short cervix found on transvaginal ultrasound surveillance, in a patient with prior preterm birth. The evidence for this approach is stronger than for history-indicated cerclage in patients without prior PTB.
Physical exam-indicated (rescue) cerclage
Cerclage placed in response to cervical dilation found on physical examination, often with bulging membranes. Also called emergency cerclage. Evidence is more limited; requires ruling out infection, labor, and abruption before placement.
Vaginal progesterone
A medication inserted vaginally daily that may reduce preterm birth risk. SMFM recommends it as first-line treatment for a short cervix (under 20mm) in patients without prior preterm birth. It may be used alongside cerclage in some situations or as an alternative to cerclage in others.
Chorioamnionitis
Infection of the membranes and fluid surrounding the baby. A contraindication to cerclage placement. Must be ruled out before any cerclage is considered, particularly in the setting of dilated cervix or ruptured membranes.
17-OHPC (17-alpha hydroxyprogesterone caproate)
An injectable progesterone that was previously used to prevent preterm birth. The FDA withdrew approval in April 2023 due to lack of efficacy. SMFM no longer recommends it, including compounded formulations.