How you prepare

By Mayo Clinic Staff

Before cervical cerclage, your health care provider will likely do an ultrasound to check your baby's vital signs and rule out any major birth defects. Your health care provider might also take a swab of your cervical secretions or do amniocentesis — a procedure in which a sample of amniotic fluid is removed from the uterus — to check for infection. If you have an infection that requires antibiotics, ideally you'll complete treatment before the cerclage is done. If your cervix has already begun to open or an ultrasound shows that your cervix is short, however, your health care provider might give you antibiotics shortly before the procedure to reduce the risk of infection. Also, your health care provider might recommend avoiding sex for at least one week before the procedure.

Ideally, an elective cervical cerclage is done between weeks 12 and 16 of pregnancy. An emergency or rescue cerclage, however, can be done up until week 24 of pregnancy if a pelvic exam or ultrasound shows that your cervix is beginning to open. Cervical cerclage is typically avoided after week 24 of pregnancy due to the risk of rupturing the amniotic sac and triggering premature birth. In some cases, cervical cerclage can be done before pregnancy.

If you have prolapsed fetal membranes — a condition in which the amniotic sac protrudes through the opening of the cervix — and your health care provider recommends cervical cerclage, he or she will treat the condition before doing the procedure. Your health care provider might place a thin tube (catheter) in your urethra to fill your bladder and reposition the amniotic sac. Alternatively, your health care provider might insert a balloon-tipped catheter beyond the opening of your cervix and inflate the bulb to push the amniotic sac back into place.

Feb. 18, 2012