A cause of miscarriage and preterm birth in the later stages of pregnancy, cervical incompetence is a condition in which the cervix begins to open (dilate) and thin (efface) before a pregnancy has reached full term. In a woman with cervical incompetence, dilation and effacement of the cervix occur without pain or uterine contractions. Instead of happening in response to uterine contractions, as in a normal pregnancy, these events occur due to a weak cervix that cannot withstand the pressure exerted by the growing uterus. If the changes are not halted, rupture of the membranes and premature birth can result.
Having an incompetent cervix does not mean you are inadequate or, as the term suggests, incompetent. The term “incompetent” in this sense simply means that the muscle of the cervix is not able to withstand the pressure of the uterus. Because you cannot voluntarily control this muscle, it cannot possibly be due to any failure on your part. Read on to learn more about cervical incompetence.
Key Points
- Cervical incompetence can cause miscarriage and preterm birth in the later stages of pregnancy, occurring when the cervix opens and thins before reaching full term, due to a weak cervix that cannot withstand the pressure from the growing uterus.
- Causes of cervical incompetence can vary but may include previous cervical operations, cervical damage from difficult deliveries, or cervical malformation due to birth defects.
- Symptoms include spotting or bleeding, mucus-like vaginal discharge, and a sensation of pressure in the lower abdomen.
- Treatment options include cerclage, a surgical technique to reinforce the cervical muscle, typically performed around 18-20 weeks of pregnancy.
What Causes Cervical Incompetence and Who Is At Risk?
Cervical incompetence is a relatively rare condition, occurring in a small percentage of all pregnancies. It is thought to cause a significant number of miscarriages in the second trimester. These causes vary and can include:
- Previous cervical operations such as dilation and curettage (D&C) or biopsy
- Cervical damage from a challenging previous delivery.
- Cervical malformation due to a birth defect, such as exposure to DES (diethylstilbestrol).
These risk factors make it more likely for the problem to recur in subsequent pregnancies. Other women at risk for this problem include those who are pregnant with more than one fetus and those experiencing excessive amniotic fluid (hydramnios) in their current pregnancy. For these women, cervical incompetence is less likely to recur in a subsequent pregnancy.
What are the Symptoms of Cervical Incompetence?
The symptoms of cervical incompetence may resemble those of miscarriage or preterm labor. When the following signs or symptoms occur in the absence of abdominal pain, cervical incompetence may be the cause:
- Spotting or bleeding.
- A vaginal discharge that is bloody or thick and mucus-like (the latter may be the passing of the mucus plug from the cervix).
- A sensation of pressure in the lower abdomen.
You need to be especially alert to these signs if you had a miscarriage or preterm labor in a previous pregnancy which was due to cervical incompetence. Some attempts have been made to diagnose cervical incompetence before it causes problems, but these efforts have not been very successful.
What Treatments Are Available For Cervical Incompetence?
If you were diagnosed with cervical incompetence in a previous pregnancy, your doctor might recommend preventative measures during your current pregnancy. Treatment may include cerclage, a surgical technique to reinforce the cervical muscle. Several procedures are used for the cerclage, but they all involve placing sutures above the opening of the cervix to narrow the cervical canal.
Cerclage is most successful if performed around 18 to 20 weeks of pregnancy. Depending on what type of procedure was used, the sutures may either stay in place or be removed close to your due date. Placement of a cervical cerclage does not completely protect a woman from miscarriage or preterm delivery. Additional treatment, such as bed rest or tocolytic therapy (medication to suppress contractions), may also be recommended. Even with a cerclage and additional therapy, the risk of preterm birth is high (about 25 percent in some studies) in women with cervical incompetence.
Cervical incompetence can be a significant concern during pregnancy, potentially leading to miscarriage and preterm birth. Understanding its causes, symptoms, and available treatment options is essential for managing this condition. If you have any concerns or suspect cervical incompetence, consult your healthcare provider for a proper evaluation and guidance.
The content of this article should not be considered professional medical advice. Exercise due diligence when seeking relevant health information. Always consult your healthcare provider before making any medical decisions.