The cervix is the lower part of the uterus, which is sometimes referred to as the ‘neck of the womb’. It remains tightly closed during pregnancy, and only begins to open up and stretch when Labour starts, thus allowing the baby to pass through and be delivered. However, sometimes as the baby grows and gets heavier, if the cervix is not strong it opens up and can cause a miscarriage or preterm birth, commonly in the second trimester of pregnancy. There is a slightly higher risk of this happening if one has had any previous gynaecological procedures. In many cases the cause is unknown. A cervical cerclage is a procedure that is done to prevent this from happening.
Cervical cerclage involves placing a firm stitch around the cervix in order to keep it from opening up. The stitch is then removed at term (the 37th week of pregnancy) to allow for delivery. It is a theatre procedure that is usually done as a day case (meaning that you would be able to go home on the same day), and is generally safe. There are three major reasons for your doctor to recommend a cervical cerclage:
• If you have previously had second trimester miscarriage(s), preterm delivery, or cervical cerclage in an earlier pregnancy. It is usually done at around the 12th to the 14th week of the pregnancy.
• If it is noticed during an ultrasound scan that the cervix is beginning to open up, even when there are no symptoms suggesting that the cervix is opening (e.g. pain)
• As an emergency, if it is discovered that the cervix has opened and the membranes (the sac that holds the baby) is bulging out – either from an ultrasound scan or through a vaginal examination with a speculum performed for symptoms such as vaginal discharge, bleeding or a sensation of pressure.
In most cases, this procedure is done through the vagina. However, if one has had repeated failed cervical cerclages through the vagina, it can be done through the abdomen, in which case the stitch is placed much higher up on the cervix. The procedure can be done either through a laparoscopic surgery, where two or three small cuts are made on the abdomen and the operation performed with some special instruments, or through an open surgery, where a bigger cut is made on the lower abdomen.
Before the surgery, some tests will be done to check your blood level, blood clotting functions, and blood group. If an abnormality is detected or if you have been known to have a previous illness, you might need to be seen by another doctor to be cleared for surgery.
For this surgery, you will have the choice of either being put to sleep (general anaesthesia), or being numbed from the waist down (spinal anaesthesia), as long as there are no other medical contraindications involved. However, a laparoscopic abdominal cerclage can only be done under general anaesthesia.
A vaginal cervical cerclage takes about 30 to 45 minutes, while an abdominal cervical cerclage takes about 1 hour. After the procedure, you will be observed for a few hours in the hospital, and discharged home on either the same day or the following day. If you had an abdominal cerclage, you might have to be on admission for 2 or 3 days. It is not uncommon to experience some vaginal bleeding (spotting), and mild cramps after the procedure, which will stop in a day or two. You will be placed on oral antibiotics, analgesics, and tocolytics (a drug to prevent the uterus from contracting). Before discharge, you will have an ultrasound scan done to confirm that your baby is alright. Subsequently you will be seen after a few days to check that the stitch is intact, then either weekly or every two weeks.
A cervical cerclage CANNOT be performed if any of the following occurs:
• Active labour
• Bleeding actively from the vagina
• Membranes (the sac holding the baby) have already ruptured and there is drainage of liquor (the fluid surrounding the baby)
• An infection of the membranes called chorioamnionitis.
Unfortunately, a cervical cerclage is not always effective, and sometimes a miscarriage can still occur, especially where a rescue cerclage was done.