Incompetent cervix

In a normal pregnancy the cervix (the opening of the womb at the top of the vagina) remains tightly closed until the baby is ready to be born, at which point it starts to open up. In a small percentage of cases, though, the cervix isn't strong enough to stay closed, and when the weight of the baby gets to the point where the cervix can't hold it any more - usually from around 3-4 months - it slowly begins to open up. This leads to a miscarriage or the baby being born prematurely. When this happens, it's known as an incompetent cervix.

• How do I know if I have an incompetent cervix?
• What can be done about it?
• What causes it?

How do I know if I have an incompetent cervix?

Unfortunately, an incompetent cervix cannot be diagnosed until a woman has already had one or more miscarriages or given birth to one or more babies prematurely. Another indication that a cervix is incompetent is that it opens up without the mother being aware of it and without her feeling any pain. A doctor can determine whether it is open with an internal examination.

What can be done about it?

If you've been diagnosed as having an incompetent cervix, the treatment for your next pregnancy is to have a stitch inserted to hold your cervix closed, rather like putting a wire tie round a plastic bag. This is usually done when you're around 12-14 weeks pregnant, under a general anaesthetic. There's no risk to the baby from this procedure. The stitch is then removed at around 36-38 weeks, generally without needing an anaesthetic. Labour often begins shortly after the stitch has been taken out.

If you've had a stitch inserted, and you go into labour before it's been removed, you should go to hospital straight away to have it taken out.

What causes it?