If you have ever been told that you have cervical insufficiency, a weakened cervix, or a short cervix, or if you had a late miscarriage or a very premature baby in a previous pregnancy, your obstetrician may talk with you about a procedure called cervical cerclage. The procedure is also called a cervical stitch or a purse-string suture.
Essentially, a cervical cerclage is done to help keep the cervix of your uterus closed so that your pregnancy can progress. It can help reduce your risk of losing your pregnancy or of having a premature baby, but it does not completely eliminate that risk.
If you think of your uterus as an upside-down bottle, the cervix of the uterus is the neck and opening of the bottle. It stays closed during your pregnancy, but starts to soften and dilate, or open up, in the two or three last weeks of your pregnancy. Cervical insufficiency is also called having an incompetent cervix and it means that the cervix is not staying shut or is dilating too early. A short cervix is one that is less than 25 millimeters or about an inch long at the 18th to 24th week of pregnancy. Starting out with a short cervix is bad because the cervix normally grows shorter as a pregnancy progresses.
A weak or short cervix is thought to be the cause of about one in four miscarriages during the second trimester.
In one type of a cervical cerclage, the McDonald procedure, an obstetrician-gynecologist uses a needle and runs a suture around your cervix and pulls the sutures snug before tying it closed. In another type, the Shirodkar procedure, the surgeon makes small incisions in the cervix and then runs a thin tape through those incisions. As with the sutures, the tape is pulled snug and tied off so that the cervix is held closed.
A cerclage is usually done transvaginally, that is, through the vagina. Your obstetrician uses a speculum to hold your vagina open and then uses forceps to hold the cervix steady while the sutures or tape is put in place. A transvaginal cerclage can be done in a doctor’s office, a surgical center, or a hospital.
A cerclage can also be done transabdominally, through an incision on the abdomen. The incision may be large enough for the doctor to raise the uterus up and place a tape around the lower part of the uterus where it meets the cervix, or it can be done laparoscopically, which means that a small incision is used, and the doctor looks at what he or she is doing using special camera equipment. With a transabdominal cerclage, you may need to undergo a cesarean section when you deliver your baby.
Usually, you go home right after the cerclage procedure, although you might stay overnight in the hospital if it is done abdominally. You may have some mild cramping, some light bleeding, or a discharge from your vagina.
Cerclage is not recommended for a pregnancy with multiple babies. It is also not recommended if your waters have already broken or if you are already in preterm labor.
If you have had a pregnancy loss or premature birth in the past, your doctor may schedule a cerclage procedure between the 12th and 14th week of your pregnancy. A cerclage can be done up to the 24th month of a pregnancy but is generally not done after that time because the procedure could increase the risk of a miscarriage at that point.
The cerclage is removed during the 37th week of your pregnancy, which is about three weeks before you are due to give birth.
Although a cervical cerclage can help prevent a miscarriage or a very premature birth, there are some risks, as there are with any surgical procedure. These risks include infection, excessive bleeding, premature contractions, a premature rupture of the amniotic membranes, or a miscarriage or premature birth. These complications are very rare and most women who have a cerclage do not have serious problems.
However, a pregnancy loss or premature birth is still possible with a cerclage. If you have contractions, cramps, or abdominal pain while the cerclage is still in place, call your healthcare provider as soon as possible. Call your healthcare provider if your water breaks, if you experience heavy or persistent bleeding, develop fever or chills, or have a foul-smelling discharge from your vagina.