Cervical incompetence: what is it and how can it be treated?
Sandhya and her husband are devastated. She has just miscarried for the third time. She had really hoped that things would go well in this pregnancy but at five months she expelled the baby. There was no pain at all. She just felt the water bag break and the next thing she knew, the baby was slipping out of her.
Sandhya has cervical incompetence, also known as cervical insufficiency. Luckily, this is a treatable cause of pregnancy loss. She has a good chance of having a baby if she undergoes the correct treatment.
Sumitra, however, was luckier. She had gone for a routine ultrasound in the fifth month of her pregnancy. During the ultrasound examination, the doctor found that the cervix was gradually opening up though she had no pains at all. Her obstetrician immediately saw her. An emergency procedure called cerclage was performed and she was able to carry the baby to full term.
What is cervical incompetence?
One of the common causes of recurrent miscarriage is an incompetent cervix. In this condition, the muscle fibres of the cervix (mouth of the uterus) are weak. In a normal pregnancy, the cervix stays closed and holds the baby in the uterus till labour starts at the end of the pregnancy. However, in cervical incompetence, once the baby reaches a certain weight, the cervix is not able to hold the baby and starts opening without any pain. This usually happens between the fourth and seventh month of pregnancy. The woman may feel some pressure in the lowest part of her abdomen, may have excessive mucous-like discharge and then if no treatment is given, loses the baby.
What causes cervical incompetence?
Sometimes there is no known cause for the cervical weakness. The weakness may be inherent in the cervix; in other words, the woman is born with the weakness. In this situation, the problem may arise with the very first pregnancy. Occasionally, it may occur after the woman has undergone surgery on the cervix. However, it is important to remember that if the problem arises in one pregnancy, all subsequent pregnancies will have the same problem.
Can we predict cervical incompetence?
Unfortunately, most of the cases of cervical incompetence cannot be predicted. Once a woman has had one pregnancy with painless expulsion of the baby with or without the water bag breaking, it is almost certain that she will continue to do this with every subsequent pregnancy. Sometimes, a woman may be found to have a very short cervix either on physical examination or by ultrasound scanning and this may be an indication that she may have an incompetent cervix.
What is the treatment for cervical incompetence?
Since the problem is that of the cervix opening up, the treatment involves keeping the cervix tightly closed till the pregnancy reaches full term. This is accomplished by a procedure called cervical cerclage. If a woman has had cervical incompetence in a previous pregnancy, then in the next pregnancy a stitch is placed on the cervix. This stitch, which is placed around three-and-a-half months (14 weeks) of pregnancy, keeps the cervix tightly closed till term. Sometimes, the stitch is placed when the woman comes in with the cervix already opening up. This is called an emergency cervical cerclage.
Sometimes labour may start prematurely even after a cerclage but usually if the baby has crossed eight months, it can survive. If labour does not start on spontaneously, the stitch may be removed two weeks before the due date and labour induced.
After a cervical cerclage
A cervical cerclage is a surgical procedure that requires hospitalisation for two to three days. After going home, the woman gradually resumes normal activity. She can carry on all housework. She can also go to work after two to four weeks, if she is a working woman. Certainly there is no need for complete bed rest.
Can a cervical cerclage fail?
A cervical cerclage will usually be successful in 90 per cent of women. However, it can fail in 10 per cent and the woman may lose her baby. An emergency cervical cerclage has a much greater chance of failing.
What if cervical cerclage fails?
In women who have had two or more failed cervical cerclages, or have a very short cervix, an abdominal cerclage(bold) can be used and will succeed in taking the pregnancy to term. This is a major surgery and is required in a small number of women.
The author is an obstetrician and gynaecologist practising in Chennai and has written the book 'Passport to a Healthy Pregnancy'.