Revisiting the short cervix detected by transvaginal ultrasound in the second trimester: Why cerclage therapy may not help

Multicenter Randomized Trial of Cerclage for Preterm Birth Prevention in High-Risk Women With Shortened Midtrimester Cervical Length

“…We recognize that other investigators have extended this temporal window to include more of the mid-trimester. 10 To the extent that some of our highrisk patients may have continued to experience pathologic cervical shortening after completion of ultrasound screening (as evidenced by the 10 women who later presented with acute cervical insufficiency and underwent physical exam-indicated cerclage), and who may also have benefitted from earlier cerclage placement, our findings may have underestimated the utility of the intervention in this population.…”

“…4 Ultrasound studies 5,6 showing that the cervix appeared to shorten without contractions in women destined for preterm birth led many to consider cerclage as prophylaxis, [7][8][9] but several randomized trials have not supported this practice. [10][11][12] Althuisius et al observed a significant benefit in a small clinical trial of women whose history or symptoms suggested cervical insufficiency; preterm birth before 35 weeks of gestation was observed in 44% of the no-cerclage group versus none of the women who were assigned to receive cerclage (p = 0.002). 13 Larger trials 10,11 included women with various historic risk factors for spontaneous preterm birth: Rust et al 10 observed rates of preterm birth before 34 weeks of gestation in 35% of cerclage-group women versus 36% of controls.…”

“…[10][11][12] Althuisius et al observed a significant benefit in a small clinical trial of women whose history or symptoms suggested cervical insufficiency; preterm birth before 35 weeks of gestation was observed in 44% of the no-cerclage group versus none of the women who were assigned to receive cerclage (p = 0.002). 13 Larger trials 10,11 included women with various historic risk factors for spontaneous preterm birth: Rust et al 10 observed rates of preterm birth before 34 weeks of gestation in 35% of cerclage-group women versus 36% of controls. Berghella et al 11 also observed similar rates of preterm birth before 35 weeks of gestation regardless of group assignment: 45% in the cerclage group versus 47% in controls.…”

Pregnancy Outcome in Short Cervix: Progesterone vs Cervical Encerclage.

“…"Despite the 50 years that have elapsed since the introduction of cerclage as a procedure, there is conflicting evidence about its efficacy for standard indications (i.e. prophylactic) or for some patients with a sonographic short cervix.Several randomized clinical trials have been conducted to date which have yielded mixed results [31][32][33][34][35][36][37][38] A meta-analysis of randomized clinical trials of patients with a prior history of preterm birth and a short cervical length (<25mm) suggests that cervical cerclage is effective in reducing the rate of preterm birth and perinatal morbidity/mortality. 158 A different meta-analysis has suggested that women with a prior spontaneous preterm birth and singleton gestation may be monitored safely with transvaginal sonographic cervical length measurements 39 .…”

Screening for Preterm Labor

“…Only two prospective randomized trials have been published so far. In the first of that Rust et al, 76,77 examined 113 patients between 16 and 24 weeks. All of them had cervical funneling >25% of the total cervical length, or a shortened distal cervix < 25 mm and were randomly assigned to McDonald cerclage or no cerclage.…”