Cervical length in late second and third trimesters: a mixture model for predicting delivery

Abstract

Objectives To examine the distribution of cervical length (CL)

Implementation of universal screening for preterm delivery by mid‐trimester cervical‐length measurement

“…Amongst women who delivered preterm, a significant proportion belonged to the short‐cervix group and this was more prominent the earlier the PTD occurred. Similarly, we have described previously a mixture model for third‐trimester CL (24–40 weeks) in which a quarter of the population formed the short‐cervix group in which the majority (89%) of PTD arose. These findings suggest that, in the second, as well as in the third trimester, there is a considerable proportion of women with a short cervix, containing a significant fraction of PTD.…”

Cervical length at 11–40 weeks: unconditional and conditional longitudinal reference ranges

“…The association of short CL with early delivery has mainly been studied in the second trimester but there is emerging evidence suggesting that early assessment in the first trimester may identify women at risk for PTB, albeit with lower detection rates . Additionally, in line with the original observation of Iams et al , we have lately shown that the third‐trimester CL measurement is more sensitive than the second‐trimester measurement in predicting PTB . Yet thus far, studies on third‐trimester CL use it mainly as a predictor of the time of delivery .…”

“…Overall, first‐trimester CL seems to predict late miscarriage, second‐trimester cervical assessment performs well for very early PTB and late third‐trimester CL measurement is better for identifying late prematurity . The appropriate longitudinal chart is crucial in a sequential approach because it enables the quantification of CL change.…”

Prediction of Preterm Delivery by Late Cervical Length Measurement after 24 Weeks

“…We have previously demonstrated that late second- and third-trimester CL is useful in the estimation of the probability for SPD [20]. The present study provides evidence on the value of CL measurement after 24 weeks for the prediction of SPD, suggesting that there is place for a repeat examination of the cervix in the early third trimester.…”