Cervical Incompetence
When the cervix opens too early in pregnancy
Quick Facts
- Type: Pregnancy complication
- Problem: Cervix opens early without contractions
- Main risk: Late miscarriage or preterm birth
- Often treated with: A cervical stitch (cerclage)
Overview
Cervical incompetence, also called cervical insufficiency, is a condition in which the cervix—the lower opening of the uterus—begins to open (dilate) and thin (efface) too early in pregnancy. Normally the cervix stays firmly closed until labor begins. When it opens prematurely, usually in the second trimester and without painful contractions, it can lead to late miscarriage or preterm birth.
This condition is closely related to cervical insufficiency and may be suspected after a previous mid-pregnancy loss or detected on ultrasound. With careful monitoring and, when appropriate, treatment such as a cervical stitch, many pregnancies can continue safely closer to full term.
Symptoms
Cervical incompetence often causes few or no symptoms, which is part of what makes it concerning. When signs do occur, usually in the second trimester, they may include:
- A feeling of pelvic pressure or heaviness
- A backache
- Mild abdominal cramping
- A change in vaginal discharge, sometimes increased, watery, or tinged with blood
- A sensation that something is bulging in the vagina
Because symptoms can be subtle, women with risk factors are often monitored with ultrasound. Any new pelvic pressure, leaking fluid, or bleeding in pregnancy should be reported promptly.
Causes
The cervix may be weak from birth or become weakened by earlier events. Contributing causes include:
- Previous cervical surgery or procedures: Such as treatment for abnormal cervical cells or a prior dilation procedure.
- Cervical injury: Tears during a previous birth.
- Congenital differences: A cervix that is naturally shorter or weaker.
- Connective tissue differences: Conditions affecting the strength of supporting tissues.
- Previous mid-pregnancy loss: A history that suggests the cervix opened too early before.
In some cases, no clear cause is found.
Risk Factors
- A previous second-trimester miscarriage or preterm birth
- Prior surgery or procedures on the cervix
- Injury to the cervix during a past delivery
- A naturally short cervix seen on ultrasound
- Connective tissue disorders
- Carrying more than one baby (in some cases)
Diagnosis
Diagnosis is based on history and ultrasound, and sometimes on examination findings. It may involve:
- Medical history: A pattern of painless second-trimester losses raises suspicion.
- Transvaginal ultrasound: Measuring the length of the cervix; a short cervix can signal increased risk.
- Pelvic examination: Checking whether the cervix has begun to open.
- Serial monitoring: Repeated ultrasounds in women at higher risk.
Treatment
Treatment aims to keep the cervix closed and the pregnancy progressing. Options depend on the situation and may include:
- Cervical cerclage: A stitch placed around the cervix to help hold it closed, usually removed before delivery.
- Progesterone: Hormone treatment that may help reduce the risk of preterm birth in some women.
- Activity adjustments: Reduced activity in some cases, guided by the care team.
- Close monitoring: Regular check-ups and ultrasounds to watch the cervix.
- Pessary: A supportive device used in selected cases.
The best approach depends on a woman's history, how far along the pregnancy is, and ultrasound findings, and is decided together with the obstetric team.
Prevention
- Tell your care team about any previous mid-pregnancy losses or preterm births
- Attend recommended prenatal visits and ultrasound monitoring
- Report pelvic pressure, leaking fluid, bleeding, or unusual discharge promptly
- Follow guidance on activity and treatment such as progesterone or a cerclage
- Avoid smoking and follow general healthy-pregnancy advice
When to See a Doctor
Contact your obstetric provider promptly if you notice pelvic pressure, a backache, cramping, increased or bloody discharge, or a sensation of bulging during pregnancy. Seek emergency care for:
- A sudden gush or steady leak of fluid from the vagina
- Heavy vaginal bleeding
- Strong or regular contractions before term
- A feeling that the baby or membranes are coming down
Frequently Asked Questions
What is cervical incompetence?
Cervical incompetence, also called cervical insufficiency, is when the cervix opens too early in pregnancy without painful contractions. This usually happens in the second trimester and can lead to late miscarriage or premature birth.
What are the warning signs?
Signs can be subtle and may include pelvic pressure, a backache, mild cramping, increased or bloody discharge, or a sensation of bulging in the vagina. Because symptoms are easy to miss, women at risk are often monitored with ultrasound.
How is cervical incompetence treated?
Treatment may include a cervical stitch (cerclage) to help hold the cervix closed, progesterone, close monitoring, and sometimes reduced activity. The right approach depends on your history and ultrasound findings and is chosen with your obstetric team.
Can I have a healthy pregnancy with cervical incompetence?
Yes. With early identification and treatment such as a cerclage or progesterone, many women carry their pregnancies much closer to term. Attending prenatal visits and reporting symptoms promptly are important.
When should I seek emergency care?
Seek urgent care for a gush or steady leak of fluid, heavy bleeding, regular contractions before term, or a feeling that something is coming down through the cervix. These may signal that the pregnancy is at immediate risk.
References
- American College of Obstetricians and Gynecologists (ACOG).
- Mayo Clinic. Incompetent cervix.
- MedlinePlus, U.S. National Library of Medicine. Cervical insufficiency.
- National Institute of Child Health and Human Development (NICHD).