Cervical Insufficiency or Cervical Incompetence is the inability of the uterine cervix to remain closed and to hold the pregnancy til term.
For different reasons the uterine cervix becomes short or weak. The increasing weight of the fetus and gestational sac promotes cervical dilatation early in the pregnancy resulting on the delivery of a very premature baby and, in many cases, fetal loss.
Frequently Asked Questions
Q. What are the symptoms of Cervical Insufficiency ?
Cervical Insufficiency does not have clinical signs or symptoms of itself and unfortunately the diagnosis is commonly made after a fetal loss that happened during the second or early third trimester. The typical history is of two or more losses that happen at earlier gestational ages each time. These happen after
'silent' dilatation of the cervix without painful contractions or heavy bleeding.
Q. How do I know if I have Cervical Insufficiency ?
Unfortunately the diagnosis can only be made once a woman falls pregnant. The dilatation of the cervix tends to occur in the absence of specific symptoms; therefore, in most cases by the time it is found that there is something wrong it is too late and the woman ends up losing the baby.
Q. Is it possible to suspect that a woman has Cervical Insufficiency before losing a baby ?
Some women are more likely to develop Cervical Insufficiency. The two most common factors are:
- Previous surgery to the cervix to treat cervical cancer or cervical dysplasia
- Uterine anatomic congenital malformations
In those cases a program of ultrasonographic surveillance of the cervix should be done even in the first pregnancy and a Cervical Cerclage inserted if the ultrasound shows signs of cervical shortening or cervical dilatation.
Q. What is the treatment for Cervical Insufficiency ?
Cervical Insufficiency is treated by placing a suture around the cervix to try to keep it closed. There are different ways of doing it:
- Elective Transvaginal Cerclage
The most common treatment for Cervical Insufficiency where a suture is placed around the cervix approaching it from the vagina at around 14 weeks gestation.
- Ultrasonographic Cervical Surveillance and Transvaginal Cerclage at signs of cervical dilatation.
This is a more conservative approach usually taken when the diagnosis is uncertain. Weekly ultrasounds are performed to measure the length of the cervix. If it is shown to be shortening or if there are signs that the cervix is starting to open, a transvaginal suture is then placed around the cervix.
- Transabdominal Cerclage
The principles of the Transabdominal Cerclage are the same as the Transvaginal Cerclage, to place a suture around the cervix in order to prevent it from opening early in the pregnancy. The difference is that done through the abdomen, the surgeon is able to place the suture at a significantly higher level at the top end of the cervix. Potential benefits are a better closure of the cervix near the internal cervical orifice and the absence of suture material in the vagina reducing the chance of infection. A possible disadvantage is that the suture is not removed requiring a caesarean section to deliver the baby.
Women who are considering a Transabdominal Cerclage usually have a sad and emotional previous obstetric history with two or more losses in the second trimester.
Each case should be assessed individually and the decision to perform an abdominal cerclage should be made after a long discussion between the patient and the clinician.
At present indications for a Transabdominal Cerclage include:
- Previous failed Transvaginal Cerclage
- Previous surgery to remove part of the cervix like cone biopsies
- Shortened cervix on examination
- Laparoscopic Transabdominal Cerclage
The procedure is similar to the Transabdominal Cerclage, but is done through laparoscopy (keyhole surgery). The benefits are that the operation is less invasive, with only three small (less than 1 cm) incisions. Most women go home the same day or the following morning. It is less painful than the open Transabdominal Cerclage where an incision similar to the one done for a caesarean section is used. Return to normal activities is also faster with most women back to work after 7 to10 days.
Q. How do I know which procedure is best for me ?
Each woman's situation is unique and should be assessed individually.
It is difficult to come up with a definitive answer that can be used for all cases.
The reasons are:
- The physiology of the cervix is not entirely understood and it is not known why the cervix of women in very similar conditions will behave differently.
- The results from clinical trials are in statistical figures and are good for general populations but don't necessarily translate to individual cases.
- The trials necessary to reach more reliable answers are difficult to conduct and have not been done yet. For example, it would be necessary to recruit large numbers of women with Cervical Insufficiency and randomly assign them to two different groups one having the Transvaginal Cerclage and one having the Transabdominal Cerclage. Trials like these have ethical and emotional constraints.
In general, Transvaginal Cerclage is the first treatment to be considered for most cases and the transabdominal or laparoscopic approaches are limited to the situations outlined above. With the good results and reduced morbidity of the Laparoscopic Cervical Cerclage, we may see an increase in indications for the procedure.