The diagnosis of cervical incompetence is usually suspected on the basis of the following history:
- Second trimester miscarriage or premature birth, in which both bleeding and painful contractions are minimal
- No prior warning symptoms or signs in most cases
- Where the bulging membranes often breaks followed by a sudden gush of water per vagina that heralds the onset of miscarriage or premature birth.
- A physician inadvertently detects a partially dilated and shortened cervix by pelvic examination performed in the mid-trimester of pregnancy.
Once, the diagnosis of cervical incompetence is suspected and before the next pregnancy is planned, the following may be useful:
- A hysterosalpingogram (HSG-dye or x-ray test) to evaluate the anatomical transition from endocervical canal to the uterine cavity and to detect a deformity (congenital or acquired) of the uterus, that can also lead to mid-trimester miscarriage and premature birth.
- A vaginal ultrasound examination to measure the length of the cervical canal (it should measure more than 2.5 cm) and to exclude pathology of the uterine muscle layer called myometrium (e.g. fibroids)
- A diagnostic hysteroscopy to evaluate uterine scarring, fibroids protruding into or distorting the uterine cavity and for the congenital deformities such as uterine septum, septate uterus, arcuate uterus, etc.
Cervical incompetence is treated by the placement of a temporary circumferential non-absorbable tape or suture around the neck of the cervix at the 12th to the 14th week of pregnancy (cerclage). The advantage of this approach is that the cerclage can readily be removed a week or two before delivery, thereby allowing a subsequent spontaneous vaginal birth to take place. The disadvantage of placing a cerclage is the risk of puncturing the fetal membranes while inserting the stitch. When correctly placed (high up in the cervico-vaginal junction), cerclage is believed to be effective in preventing premature opening of the cervix. In all cases of poor prior pregnancy outcome, other causes should be considered and testing done accordingly prior to placement of a cerclage. Dr. Bayrak recommends a consultation with an infertility specialist as well as a maternal fetal medicine (MFM) specialist in cases of suspected or documented cervical incompetence.