Cervical cerclage is a procedure used to prevent preterm delivery due to cervical insufficiency. Normally, the cervix doesn’t begin to open until the startof labor, but, sometimes, as the fetus grows, it can place pressure on the cervix causing it to open too early. When the cervix can’t retain a pregnancy through the second trimester of pregnancy even though no contractions have occurred, a woman may be diagnosed with cervical insufficiency.
Obstetricians consider cervical cerclage for women with a history of second trimester pregnancy loss due to painless cervical dilation, those with prior cervical cerclage placement for cervical insufficiency, patients who have experienced past spontaneous preterm birth earlier than 34 weeks’ gestation and short cervical length before 24 weeks’ gestation or those in whom cervical dilatation was noted on physical exam in second trimester.
The cervix is located at the bottom of the uterus and opens into the vagina. When weak, the cervix can soften and dilate leading to premature delivery. Cervical cerclage helps prevent pregnancy loss by keeping the cervix closed until the fetus reaches a viable stage. Sutures or a synthetic band is placed around the cervix during the 13th or 14th week of pregnancy and remains in place until week 36. Women who undergo cervical cerclage are required to remain on bed rest until delivery.
Obstetricians may perform cervical cerclage by entering through the vagina or by making a small incision in the lower abdomen. During vaginal procedures, instruments are passed through the vagina to the cervix where sutures are placed for closure. Ultrasound may be used for guidance.
OBGYNs may also carry out the procedure through a small incision in the lower abdomen. This technique is sometimes used following a failed vaginal approach or when there are anatomical conditions that will make a vaginal approach difficult or impossible. In this case, a synthetic band is positioned around the cervix to prevent it from opening.
There are relatively few risks associated with cervical cerclage. A majority of women who undergo this procedure deliver viable infants, although there are a higher percentage of premature deliveries. Around weeks 36-37, the sutures are removed to prepare for delivery. If an abdominal approach was used, a C-section may be scheduled allowing the cerclage to be removed at the time of delivery. Some women may opt to leave the cerclage in place for future pregnancies.