There are two main types of cervical suture that are put in through your vagina. The first is the Shirodkar suture. For this we insert the tape under the surface of your cervix near the top, where your cervix meets your uterus. The second type is the MacDonald suture. We insert this lower down on your cervix. It is a “purse string” type of suture that is not completely buried within your cervix.
If your cervix is already dilating we may use a third type of suture. This is called a rescue cervical suture. It is similar to a MacDonald suture but we may use a different type of tape. For a rescue cervical suture to be possible you must have no infections present and no early signs of labour such as contractions.
What has gone wrong?
Your cervix may be weak because of:
- previous surgery to your cervix, such as a cone biopsy
- previous damage to your cervix, perhaps from repeated terminations of pregnancy
- a weakness that you have had since birth
- an increase in pressure on your cervix from a multiple pregnancy such as twins or triplets
Women with a short cervix are more likely to have a late miscarriage or go into labour early than those with a longer cervix. The cause of differences in the length of the cervix is not fully understood.
The aim
The aim of a cervical suture is to support your cervix to stop it dilating before your pregnancy reaches full term. We do this by inserting mersilene tape into your cervix using a needle. The tape encircles your cervix and so it may be called a cervical cerclage. We remove the cervical suture before you give birth, usually around week 37 of pregnancy.
The benefits
This operation can reduce your chance of miscarriage and may prevent a very premature birth.
Are there any alternatives?
If the Shirodkar or MacDonald suture should fail it may be possible to place a different suture around your cervix from inside your abdomen. This is called an abdominal cervical suture. It is a bigger operation with more risks. This would mean making a cut in your lower abdomen to place the suture around your cervix.
What if you do nothing?
If you have an incompetent cervix and you do nothing you may miscarry or have a very premature baby. If a premature baby is delivered very early in the pregnancy the chance of survival is low. If the baby does survive the earlier it is delivered the more likely it is to have disabilities.
Who should have it done?
You should consider having a cervical suture if:
- you have had a late miscarriage before. A late miscarriage is during 15-24 weeks gestation.
- an ultrasound scan during the pregnancy shows that your cervix is shortening
- you have a multiple pregnancy and signs of a shortening of your cervix
If your cervix is dilating and you have no signs of labour or infection we may consider you for a rescue cervical suture.
Author: Dr Chineze Otigbah MRCOG. Consultant obstetrician and gynaecologist.
© Dumas Ltd 2006
