Review Article

Adjunctive Therapies to Cerclage for the Prevention of Preterm Birth: A Systematic Review

Table 2

Studies reporting the use of reinforcing cerclage.

StudyDesign Sample SizeAverage cervical length at diagnosis (mm)Cerclage typeMean gestational age (weeks) initial cerclageMean
gestational age (weeks) additional cerclage
Total number
sutures
placed
Mean latency to delivery (weeks)Mean gestational age (weeks) at deliveryOutcomeOverall rate of PTB

Fox et al., 1998 [15]Prospective cohort12/26n/aMcDonald14*20 (18–24)2–413 (4–19)34 (22–39)PTB < 37 wga
LB
75% (<37)
Baxter et al., 2005 [14]Retrospective cohort5/2414.3 ± 3.6McDonald124/7191/7214/720.8 ± 2.7PTB < 35 wga
PTB < 24 wga
100% (<35)
80% (<24)
Simcox and Shennan, 2012 [16]Retrospective cohort13/257.2 (0–15)McDonald145/7193/7264/7260/7 ± 5 1/7PTB < 32 wga
PTB < 24 wga
92% (<32)
38% (<24)
Song et al., 2011 [17]Retrospective cohort11/22n/aMcDonald17.0 ± 2.921.7 ± 2.325.1 ± 4.226.8 ± 5.0LB
BW

n/a: not available, PTB: preterm birth, wga: weeks gestational age, LB: livebirth, and PM: perinatal mortality.
Documented history-indicated cerclage was performed at 14 weeks gestation. Fifteen cases did not have documented gestational ages at initial cerclage placement.