Prediction of spontaneous preterm birth by cervical length in the first trimester of pregnancy: Comparison of two measurement methods

Abstract

Introduction Our objectives were to compare the single‐line and two‐line methods of cervical length measurement in the first trimester of pregnancy and to evaluate the potential value of the first trimester cervical length measured by the two methods in predicting spontaneous preterm birth. Material and methods This was a prospective study in singleton pregnancies at 11+0 to 13+6 weeks of gestation. Cervical length was measured by two methods: (i) a linear distance between the two ends of the glandular area around the endocervical canal (single‐line method) and (ii) a sum of a linear distance from the internal os to the greatest cervical curvature and a linear distance from this point of the cervix to the external os (two‐line method). The screening performance of the first trimester cervical length measured by the two different methods for the prediction of spontaneous preterm delivery was assessed by receiver‐operating characteristics (ROC) curve analysis. The areas under the ROC (AUROC) were compared by De Long test. Results A total of 1484 consecutive singleton pregnancies were included in this study. Spontaneous preterm delivery at <37 and <32 weeks occurred in 75 cases (5.1%) and 12 cases (0.8%), respectively. The median cervical length measured by the single‐line method was significantly shorter than that by the two‐line method (33.5 vs 36.5 mm, p < .001). Compared with the term delivery group, the median cervical length measured by the two‐line method was shorter in women with spontaneous delivery at <32 weeks of gestation (36.5 vs 33.6 mm, p < .01). No significant difference in the median cervical length measured by the single‐line method was detected between the spontaneous preterm delivery and term delivery groups. Receiver‐operating‐characteristic curves demonstrated that cervical length measured by the two‐line method achieved better performance in predicting spontaneous delivery at <32 weeks compared with the single‐line method (AUROC: 0.72 vs 0.61, p < .01). Conclusions We have demonstrated that the first trimester cervical length, measured by the two‐line approach, holds promise as a potential screening tool for early spontaneous preterm delivery.

First-trimester prediction of preterm prelabour rupture of membranes incorporating cervical length measurement

“…[12] There is, however, still controversy regarding the role of CL measurement in the first trimester in the prediction of PTB. [11,[13][14][15] Furthermore, a history of previous PTB, which is known to be an independent predictor of PTB [16], has been found to increase PPROM prediction if combined with a CL measurement in the second trimester. [17] Cervical surgery has been shown to predispose women to PTB, and this risk may be proportional to the amount of tissue removed from the cervix during the procedure.…”

Prediction of spontaneous preterm birth and preterm prelabor rupture of membranes using maternal factors, obstetric history and biomarkers of placental function at 11–13 weeks

“…However, the screening performance of the first-trimester combined model that includes maternal risk factors and biomarkers of placental function (PAPP-A and PlGF) is suboptimal. Several groups have shown that first-trimester cervical length may be a useful screening tool for sPTB [36][37][38][39][40] . Future studies should aim to evaluate whether addition of cervical length and other biomarkers will improve the screening performance of the combined model.…”

Uterocervical Angle Versus Cervical Length in the Prediction of Spontaneous Preterm Birth in Women with History of Spontaneous Preterm Birth. A Prospective Observational Study

“…Cervical length assessment in the second trimester through transvaginal ultrasound assessment is a strong predictor for spontaneous preterm birth. Cervical length ≤ 25 mm at 22 + 0 to 24 + 6 weeks of gestation has been associated with 37.3% sensitivity, 92.2% speci city, 17.8% positive predictive value, and 97.0% negative predictive value for the prediction of spontaneous preterm birth at < 35 weeks of gestation (10). The Anterior uterocervical angle is de ned as the angle between the cervix and the anterior uterine wall; this angle can be measured by ultrasound and its width can be of great value in predicting preterm birth.…”