The cervix should remain tightly closed until labour occurs at or after 37 weeks of pregnancy. In some women it opens early and, depending on the number of weeks of pregnancy, this may result in a late miscarriage or premature birth. Dr Vasso Terzidou, leading OB-GYN, explains more about the procedure, and the reasons behind performing it.
What is cervical cerclage?
Cervical cerclage is a surgical procedure performed at about 12-15 weeks into the pregnancy, inserting a stitch to the cervix – the neck of the womb - to try and keep it closed, in cases such as history of previous preterm deliveries or late miscarriages, or later in pregnancy when there is shortening of the cervical length. There are occasions that we perform cervical cerclage before pregnancy.
There are 2 main types of cerclage and usually one type will be recommended to you depending on your specific needs. Transvaginal cerclage is performed by operating from the vagina, whereas transabdominal cerclage involves a bikini‐line cut to the abdomen. An occlusion stitch is sometimes inserted vaginally and offered to a number of patients undergoing cervical cerclage.
How do I know if I should have cervical cerclage?
If you have had a previous pregnancy which has resulted in the loss of a baby, a premature birth or if you have had significant cervical surgery in the past you will be assessed by your doctor, who will look at the length of your cervix and whether or not it is open. They will discuss whether you require cervical cerclage or whether the cervix length can be monitored.
How is cervical cerclage done?
An anaesthetist will discuss pain relief for the operation. This is a spinal anaesthetic for transvaginal cerclage, and for transabdominal cerclage a general.
A spinal anaesthetic involves the injection of a local anaesthetic into the middle of your back and means you feel no pain in the lower half of your body. You are awake for the operation, will be unable to move your legs well for approximately 4 hours afterwards and will have a catheter inserted for the duration of this time. A general anaesthetic means you are asleep for the whole operation.
What are the risks of cervical stitching?
There is often a small amount of bleeding from the vagina at the time of the operation and for several days afterwards. This is rarely heavier than a period. The risk of infection is lowered by giving you a dose of antibiotics during the operation.
A more serious risk is that the pregnancy membranes are ruptured by the stitch needle and if this happens the pregnancy is likely to miscarry. This is rare when cervical cerclage operations are done as planned operations, and the risk is probably about 1%.
It is also important to remember that some women still go on to deliver their babies early, which may result in premature birth or miscarriage. Lastly, there is a very small risk of bladder damage either at the time of the operation or in the months afterwards.
What happens afterwards?
Your follow‐up will be arranged in the antenatal clinic. If your waters break, you develop an offensive discharge from the vagina or if you have regular or severe abdominal pain at any time you should tell your midwife or call the labour ward straight away. If there is any worry about infection inside your womb, or you are in labour, the stitch will normally be removed.
If everything goes well and you have a transvaginal stitch, this will be removed through the vagina at 36‐38 weeks. After the stitch is removed, we do not know how long it will take for you to go into labour and it may be hours, days or even weeks. If you have an abdominal stitch, you will need a caesarean section and the stitch will be removed at that time if you are not planning any further pregnancies.