It is typically done after cervical trauma that has caused an anatomical defect. There is the possible, though rare, side effect of infertility. The procedure is generally to observe the patient for 24 hours before performing the cerclage. During this time she will be observed for preterm labor and screened for infection. Generally this is done with the patient in the Trendelenburg position, feet above your head.
Spinal anesthesia is used to prevent pain and maternal straining during the cerclage.
Your bladder will be filled to try and move your membranes away from the os. You will be given antibiotics to help stave off infection, and Indocin to help your body ignore the prostaglandins released during the procedure. Post-operatively you will be on bed rest for the next 24 hours, possibly in the Trendelenburg position. And monitored for uterine activity. You will need to have periods of rest each day and decreased physical activity.