When is cerclage usually removed?

Most obstetricians remove a cerclage electively at 36 to 38 weeks.
 

How long after removal of a cerclage does a woman normally go into labor?

The mean time interval between elective cerclage removal and spontaneous delivery appears to be 14 days. Bisulli and coworkers found that the chance of spontaneous delivery within 48 hours after elective cerclage removal was 11% in women with cerclage who achieved 36-37 weeks in their study.

REFERENCES
1. Bisulli M, Interval to spontaneous delivery after elective removal of cerclage. Am J Obstet Gynecol. 2009 Aug;201(2):163.e1-4. PMID: PMID:19560112
2. Guzman E.R., Houlihan C., Vintzileos A., Ivan J., Benito C., Kappy K.: The significance of transvaginal ultrasonographic evaluation of the cervix in women treated with emergency cerclage. Am J Obstet Gynecol 175. 471-476.1996; PMID: PMID:8765271