CERVICAL INSUFFIENCY (Cerclage)
Cervical insufficiency is an important condition in pregnancy associated with painless shortening, softening, or opening of the cervix before labor pains begin. Medically, it is also called cervical insufficiency and is carefully evaluated, especially in terms of the risk of second-trimester pregnancy loss and preterm birth [1][2].
The cervix normally remains closed, long, and strong throughout pregnancy. As the time of birth approaches, it softens, thins, and opens. In cervical insufficiency, this process may begin earlier than expected. Therefore, regular pregnancy follow-up, questioning of risk history, and, when necessary, measurement of cervical length with transvaginal ultrasound are important [1][3][4].
The risk is evaluated more closely, especially in expectant mothers who have previously experienced a second-trimester loss, have a history of unexplained preterm birth, have undergone a surgical procedure involving the cervix, or have been found to have a short cervix in the current pregnancy [1][2][5]. In pregnancy follow-ups conducted by Assoc. Prof. Dr. Nazlı Korkmaz, early recognition of this risk group is also of great importance for protecting the pregnancy.
What Is Cervical Insufficiency?
Cervical insufficiency means that the cervix cannot provide sufficient resistance to maintain the pregnancy. This condition often develops in the second trimester without obvious pain or regular contractions. As a result, the cervix may shorten or open, which may pave the way for water breaking, late miscarriage, or preterm birth [1][2][5].
For this reason, the concepts of “cervical shortening during pregnancy” and “cervical insufficiency” are often evaluated together. However, a short cervix alone does not always mean a diagnosis of cervical insufficiency. Gestational week, previous pregnancy history, cervical length, the presence of painless dilation, and signs of infection should be interpreted together [3][4][5].
If there is no obvious risk history in the first pregnancy, the diagnosis may sometimes not be easy to make. The problem may be detected when cervical length is seen to decrease during ultrasound follow-up or, unfortunately, after pregnancy loss. Therefore, conscious follow-up from the early weeks is very valuable in high-risk pregnancies [1][2].
What Causes Cervical Insufficiency?
Cervical insufficiency does not have a single cause. In some women, the cervical tissue may be structurally weaker. In others, previous birth trauma, surgical procedures performed on the cervix, procedures such as conization or LEEP, cervical injuries, or congenital structural differences may increase the risk [1][5].
Conditions that may increase the risk of cervical insufficiency include:
- Previous second-trimester pregnancy loss
- History of unexplained preterm birth
- Painless cervical dilation in a previous pregnancy
- LEEP, conization, or similar surgical procedures involving the cervix
- Cervical trauma that developed during birth or a procedure
- Congenital structural differences of the uterus or cervix
- Detection of a short cervix in the current pregnancy [1][2][5]
However, cervical insufficiency may also develop in pregnant women without risk factors. Therefore, looking only at past history is not sufficient. The condition should be carefully evaluated, especially when a downward pressure sensation during pregnancy, mild spotting, a significant increase in vaginal discharge, or a decrease in cervical length on ultrasound is detected [1][5].
What Are the Symptoms of Cervical Insufficiency?
Cervical insufficiency may often progress silently. Some women may have no symptoms, and the problem may only become apparent during ultrasound follow-up [1][5]. When symptoms are present, the complaints are usually mild and nonspecific.
Symptoms that may be seen in cervical insufficiency include:
- A downward pressure sensation in the pelvic area
- Mild vaginal spotting
- Increase in vaginal discharge or change in its consistency
- Mild cramping in the lower abdomen
- Low back pain
- A feeling of fullness or pressure in the vagina
- Water breaking or premature rupture of membranes
Painless cervical dilation, especially in the second trimester, is a notable finding in terms of cervical insufficiency [1][5]. The critical point here is that serious cervical changes may develop even without regular and obvious contractions. Therefore, the thought “I do not have severe pain, so there is no problem” may be misleading.
How Is Cervical Insufficiency Diagnosed?
One of the most important tools in the diagnosis of cervical insufficiency is the measurement of cervical length with transvaginal ultrasound. With this method, the length of the cervix is evaluated, whether shortening is present is monitored, and, when necessary, the tendency of the cervical canal to open can be observed [1][3][5].
Especially in high-risk pregnancies, monitoring cervical length at certain intervals from the 16th week to the 24th week may be beneficial [3][4]. Detection of a cervical length of 25 mm or less before the 24th week of pregnancy is considered important in terms of preterm birth risk [3][4].
Diagnosis is not based only on a single ultrasound measurement; the patient’s previous pregnancy history, current gestational week, whether cervical dilation is present, the condition of the membranes, signs of infection, and symptoms are evaluated together [1][2][5]. When necessary, pelvic examination may also be added to the diagnostic process.
Why Is Cervical Length Important During Pregnancy?
Cervical length during pregnancy is one of the important indicators in assessing the risk of preterm birth. As the cervix shortens, the risk of preterm birth may increase. Therefore, serial measurements may be needed instead of a single check in pregnant women in the risk group [3][4][5].
The evaluation of cervical length should not be viewed only as numerical data. The appearance of the cervix, its tendency to open, gestational week, presence of multiple pregnancy, and the patient’s previous pregnancy history should be considered together [1][3][5].
In short, cervical measurement is not a result that determines fate on its own; it is a powerful tool that guides the clinical decision-making process. The measurement result must be interpreted within the overall picture of the pregnancy.
How Is Treatment for Cervical Insufficiency Planned?
Treatment for cervical insufficiency is not the same for every pregnant woman. The treatment plan is determined according to gestational week, cervical length, previous pregnancy losses, history of preterm birth, whether there is dilation in the current pregnancy, and the presence of multiple pregnancy [1][2][3][4].
In some patients, close ultrasound follow-up alone may be sufficient, while in others vaginal progesterone treatment may be appropriate, and in some patients a cervical stitch, namely cerclage, may be a more suitable option [1][3][4]. The aim is not only to keep the cervix closed, but also to help the pregnancy reach as safe a gestational week as possible.
In personalized pregnancy follow-up planned with Assoc. Prof. Dr. Nazlı Korkmaz, the risk of cervical insufficiency is also evaluated not only based on a single ultrasound result, but by considering the entire history and current findings together.
When Is Progesterone Treatment Used?
Progesterone is one of the treatment options that may help reduce the risk of preterm birth in some pregnant women with a short cervix. NICE recommends evaluating vaginal progesterone or cerclage options in certain risk groups when there is a history of previous preterm birth or pregnancy loss together with a short cervix [3]. SMFM also states that vaginal progesterone is an important option depending on patient history in singleton pregnancies where a short cervix is detected [4].
Progesterone treatment is not automatically given to every pregnant woman. The degree of cervical shortening, gestational week, previous pregnancy history, singleton or multiple pregnancy status, and current clinical picture are evaluated together [3][4].
Progesterone should not be considered a procedure that completely “eliminates” cervical insufficiency. A more accurate expression is that it is a medical approach that may support the protection of pregnancy in suitable patients. The method of use, dose, and duration must be determined by a physician.
What Is Cerclage and When Is It Performed?
Cerclage is a surgical procedure that temporarily closes the cervix with a strong stitch. RCOG defines cervical cerclage as placing a stitch around the cervix to help keep it closed [2]. ACOG also states that cerclage may help the cervix keep the pregnancy inside the uterus [1].
Cerclage may be applied especially in some pregnant women who have a strong history of cervical insufficiency, whose cervix begins to open early, or who carry high risk due to a short cervix [1][2][3].
Situations in which cerclage may be applied generally include:
- Previous history of painless second-trimester pregnancy loss
- Preterm birth or loss in a previous pregnancy due to cervical insufficiency
- Significant cervical shortening detected during ultrasound follow-up
- The cervix beginning to open on examination
- Selected high-risk pregnancies [1][2][3]
Preventive cerclage is usually planned in the early weeks of pregnancy. In its patient information, RCOG states that a cervical stitch is most often placed between 11 and 24 weeks of pregnancy [2]. Emergency cerclage may be considered if the cervix is significantly dilated; however, in this approach, the risk of infection, premature rupture of membranes, and preterm birth may be higher [2][5].
What Are the Types of Cerclage?
The most commonly used method in the treatment of cervical insufficiency is transvaginal cerclage. This procedure is performed vaginally and is the most widely used approach [1][2].
In some special cases, transabdominal cerclage may be considered. This method may come into consideration especially if previous vaginal cerclage has failed or if cerclage cannot be performed vaginally due to anatomical reasons [2][5]. Which method is suitable is determined according to the patient’s history, cervical structure, and previous pregnancy outcomes.
Cerclage is not suitable for every pregnant woman. The procedure may not be safe in cases of active bleeding, obvious infection, ruptured membranes, onset of labor, or some multiple pregnancy situations [2][5]. Therefore, the decision for cerclage should be made in a selected patient group, at the right time, and with specialist evaluation.
What Is the Process Like After Cerclage?
Pregnancy follow-up continues after cerclage. Having a stitch placed does not mean that the risk has completely disappeared. Cervical findings, signs of infection, contraction complaints, and the general course of the pregnancy should be monitored [1][2].
After cerclage, mild spotting, cramping, or short-term discomfort may be seen. However, the following symptoms require urgent evaluation:
- Severe abdominal or groin pain
- Heavy vaginal bleeding
- Water breaking
- Foul-smelling discharge
- Fever or chills
- Regular contractions
- Significant decrease in the baby’s movements
The stitch is most often removed in the final weeks of pregnancy, usually around 36-37 weeks, or earlier if labor begins earlier [1][2]. The exact timing is determined according to gestational week, birth plan, and the mother’s clinical condition.
Is Bed Rest Necessary?
Although it is commonly recommended in society, complete bed rest has not been shown to definitively prevent pregnancy loss or preterm birth. In fact, prolonged inactivity may lead to problems such as muscle loss, risk of blood clots, psychological difficulty, and a decrease in daily quality of life [5].
Therefore, it is not correct to automatically advise every patient to “stay in bed constantly.” If movement restriction is needed, its scope should be determined individually. In some pregnant women, avoiding heavy lifting, standing for long periods, or intense physical activity may be recommended; however, this decision must be made with physician evaluation.
Why Is Follow-Up Very Important in Cervical Insufficiency?
One of the most important issues in cervical insufficiency is regular follow-up and correct timing. This is because cervical changes detected early may offer a chance for more effective intervention in suitable patients [1][3][4]. In contrast, dilation detected late, especially if the membranes have bulged downward, may limit treatment options [2][5].
In high-risk pregnancies, follow-up intervals should be planned according to gestational week, previous pregnancy history, cervical length, and current complaints. Transvaginal ultrasound measurements, examination findings, and the patient’s symptoms should be evaluated together.
| Evaluation Topic | What Does It Mean? | Possible Approach |
|---|---|---|
| Previous second-trimester loss | It is a strong risk history for cervical insufficiency | Close follow-up in early weeks and evaluation of preventive cerclage in suitable patients [1][2] |
| Short cervix before 24 weeks | It may indicate an increased risk of preterm birth | Transvaginal ultrasound follow-up and evaluation of progesterone or cerclage in suitable patients [3][4] |
| Painless cervical dilation | It may suggest cervical insufficiency | Urgent evaluation according to gestational week and clinical condition [1][5] |
| Previous surgery involving the cervix | It may cause weakness in cervical support tissue | Risk-based pregnancy follow-up and cervical length monitoring [1][5] |
| Multiple pregnancy | The risk of preterm birth is generally higher | Follow-up is performed more carefully; the decision for cerclage is not routine and is considered in selected cases [4][5] |
The approach topics in the table are for general informational purposes. The final decision is made in each pregnancy by evaluating current ultrasound findings, gestational week, previous pregnancy history, and clinical condition together.
Frequently Asked Questions About Cervical Insufficiency
Cervical insufficiency is the early shortening or opening of the cervix during pregnancy without pain or obvious contractions. This condition is especially associated with second-trimester loss and preterm birth risk [1][5].
It may not always cause symptoms. When symptoms are present, mild spotting, pelvic pressure sensation, mild lower abdominal cramping, low back pain, and changes in vaginal discharge may be seen [1][5].
One of the most important evaluation methods is measuring cervical length with transvaginal ultrasound. When necessary, pelvic examination and detailed pregnancy history are also evaluated [1][3][5].
No. A short cervix may be an important risk indicator; however, it does not always mean a diagnosis of cervical insufficiency on its own. The measurement result should be interpreted together with gestational week, history, and other findings [3][4][5].
Cerclage may be considered in cases with a previous history of second-trimester loss or preterm birth, when the cervix begins to open early, or in selected cases of short cervix [1][2][3].
Cerclage is most often performed between 11 and 24 weeks of pregnancy. Preventive cerclage is usually planned in the early weeks; emergency cerclage is evaluated in the presence of current dilation [2].
The stitch is most often removed around 36-37 weeks. If labor begins earlier or a medical necessity occurs, it may need to be removed earlier [1][2].
In suitable patients, especially in some singleton pregnancies with a short cervix, vaginal progesterone may help reduce the risk of preterm birth. However, it is not recommended in the same way for every pregnancy [3][4].
Routine complete bed rest has not been shown to definitively prevent pregnancy loss or preterm birth. If movement restriction is needed, its scope should be determined individually [5].
Cerclage is not always routinely recommended in multiple pregnancies. It may be considered in some special situations; however, the decision should be made individually [4][5].
Yes. In cases detected early and followed appropriately, it may be possible to carry the pregnancy safely to later weeks. The most important point is regular follow-up and timely intervention [1][2][3].
References
- American College of Obstetricians and Gynecologists (ACOG). Cervical Cerclage. (https://www.acog.org)
- Royal College of Obstetricians and Gynaecologists (RCOG). Cervical stitch. (https://www.rcog.org.uk)
- NICE. Preterm labour and birth guideline NG25. (https://www.nice.org.uk)
- Society for Maternal-Fetal Medicine (SMFM). Consult Series #70: Management of short cervix in individuals without a history of spontaneous preterm birth. (https://www.ajog.org)
- NCBI Bookshelf / StatPearls. Cervical Insufficiency. (https://www.ncbi.nlm.nih.gov)