Cervical cerclage is a rarely used type of surgery that involves sewing shut the outlet of the uterus (cervix) to prevent it from opening before a pregnancy is carried to full term.
Cervical cerclage may be used for a woman who has given birth prematurely in a previous pregnancy and had minimal or no contractions before the birth. It may also be used when the muscles of the cervix are suspected to be weakened (incompetent cervix). The cerclage is removed if preterm labor starts or at 36 weeks of pregnancy.
WebMD Medical Reference from Healthwise