Sonographic measurement of cervical length in threatened preterm labor in singleton pregnancies with intact membranes

Abstract

Objectives (OR, 0.69; 95% CI, 19.42; 95% CI,). In the subgroup of women who did not deliver within 7 days of presentation, the incidence of delivery before 35 weeks was 7.1% (33 of 467) and the only significant independent predictor of such delivery was cervical length (OR, 0.92; 95% CI, P < 0.0001

Transvaginal cervical length measurement for prediction of preterm birth in women with threatened preterm labor: a meta‐analysis

“…Figure 2). Cervical length < 20 mm (four studies, 1263 women, 118 preterm births within 7 days (9.3%)) could predict 75.4% (95% CI, 66.6-82.9%) of preterm births within one week, with a specificity of 79.6% (95% CI, 77.1-81.9%) 7,19,30,33 . The pooled LR+ and LR− estimates were 3.74 (95% CI, 2.77-5.05) and 0.33 (95% CI, 0.15-0.73), respectively ( Figure 2).…”

“…A cut-off of 15 mm for cervical length (three studies, 1266 women, rate of preterm birth within 48 h 7.1%) predicted 71.1% (95% CI, 59.5-80.9%) of preterm births at < 48 h with a specificity of 86.6% (95% CI, 84.6-88.5%) 7,16,23 . Both sensitivity and specificity showed considerable heterogeneity across the studies, despite the theoretical similarity in cervical length methodology and the lack of obvious disparities in the selection and exclusion criteria.…”

“…A flexible definition of preterm labor most probably underlies the fact that, of women presenting with threatened preterm labor, only 7% actually delivered within 48 h from presentation (data from 1266 women) 7,16,23 and only 11% actually delivered within 1 week (data from 1781 women) 7,18 -20,23,33 . When confining our analysis to studies with both recruitment at or before 34 weeks' gestation and explicit criteria for preterm labor (certain frequency and duration of contractions ± tocographic ascertainment) 7,18,20 , the prevalence of birth within 1 week slightly increases as expected, but again it is only 12.6%, and still varied greatly across the studies, ranging from 8.4% 7 to 31.0% 20 .…”

“…However, the diagnosis of true preterm labor remains unreliable, resulting in significant over-treatment, since fewer than 10% of these women will eventually deliver within 1 week or before 35 weeks, irrespective of treatment 7 . Apart from maternal risks, hospitalization for undelivered preterm labor has a significant financial cost.…”

Cervical length for the prediction and prevention of preterm birth

“…These women can be identified by TVU CL at presentation. The women with PTL at highest risk of PTB are those with a CL of <15 mm [54].…”