Viable extreme preterm birth and some neonatal outcomes in double cerclage versus traditional cerclage: A randomized clinical trial

The pregnant women at higher risk of preterm labor, referred to the perinatal clinic of Kosar
University Hospital in Urmia district of Iran, were enrolled into a parallel randomized clinical
trial. In the investigational arm of the clinical trial, a double cervical cerclage procedure was
performed addition to McDonald cerclage. In the control group however, only McDonald cerclage
was performed. Extreme preterm labor (GA < 33 weeks) was the primary endpoint of this clinical
trial. Age, gestational age at cerclage time, and gravidity were not found to be statistically different
between the groups. Means of gestational age were 37.4 and 36.2 weeks, respectively, for the
investigational and control groups. The gestational age was 1.2 weeks longer for double cerclage
group but the difference was not found to be statistically significant. Preterm birth before 33
weeks of gestation was not experienced by any of the patients who received double cerclage, but
five women in control group developed such an extreme preterm labor (P < 0.05). The absolute
risk reduction in using double cerclage over traditional method was 18 percent (95% confidence
interval, 4%–32%). Double cerclage appeared to have higher efficacy than traditional cerclage in
preventing preterm labor <33 weeks of gestation