Cervical incompetence is basically a cervix that is too weak to stay closed during a pregnancy. Therefore resulting in a premature birth and possibly the loss of the baby, because of the shortened gestational length. It is believed that cervical incompetence is the cause of 20 - 25 % of all second trimester losses. This incompetence generally shows up in the early part of the second trimester, but possibly as late as the early third trimester.
It is generally categorized as premature opening of the cervix without labor or contractions. Diagnosis can be made either manually or with ultrasonography. The use of ultrasonography has been very helpful with the diagnosis, and is made when the cervical os (opening) is greater than 2.5 cm, or the length has shortened to less than 20 mm. Sometimes funneling is also seen, this is where the internal portion of the cervix, internal os (portion of the cervix closer to the baby) has begun to efface. The external os will be unaffected if diagnosed in time. Factors that increase the likelihood of suffering from an incompetent cervix are:
- DES exposure
- Cervical Trauma
- Hormonal influences
- Congenitally short cervix
- Forced D & C
- Uterine anomalies
If you are diagnosed after a second trimester loss or prior to pregnancy it is suspected that you will have problems with the strength of your cervix, a cerclage (stitching the cervix closed) can be performed prophylactically at approximately 14-16 weeks. It is said that the earlier you have the cerclage performed the more likely the pregnancy is to continue.
For diagnosis made during pregnancy, you must meet certain criteria before a cerclage can be performed. You are not eligible for the cerclage if you have:
- Hyperirritability of the cervix
- Your baby has already died
- You are more than 4 cm dilated
- Your water is broken