Reference ranges for cervical length by transvaginal scan in singleton pregnancies

Abstract

CxL shortened throughout the pregnancy. The chart present 5th, 50th, and 95th centile, respectively, at 23 weeks of 20 mm, 36 mm, and 47 mm; at 28 weeks of 17 mm, 33 mm, and 43 mm; and at 34 weeks of 10 mm, 29 mm, and 43 mm.

The capacity of mid‐pregnancy cervical length to predict preterm birth in low‐risk women: a national cohort study

“…We measured between 16 +0 and 21 +6 weeks of gestation, about 2–4 weeks earlier than most previous studies. It is known that CL gradually decreases with advancing gestational age . Both Salomon et al.…”

“… and Silva et al. measured a difference of 2 mm between mean CL at 20 weeks vs. at 22 weeks of gestation.…”

Developing a quality assurance program for transvaginal cervical length measurement at 18–21 weeks’ gestation

“…A variety of nomograms have shown that CL is independent of gestational age at the mid-trimester ultrasound ( Table 2). 5,10,11,21,[25][26][27][28][29] There is considerable variability between published ranges, indicating specific variability of normal CL within different populations. 4 This underscores the need for the development of a local reference range.…”

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

“…The studies that have examined CL during pregnancy are thwarted by either of three significant limitations: first, they are mainly cross‐sectional and so not appropriate for follow‐up examinations; second, they assume a normal distribution of CL and third, they do not cover the whole gestation . The aim of the present study was to create longitudinal reference ranges and develop normograms for CL in all trimesters.…”