Reference values for the cervical length measurement in the second trimester of pregnancy using the transvaginal ultrasound in a large Brazilian population

Peixoto, Alberto Borges; Caldas, Taciana Mara Rodrigues da Cunha; Alamy, Ana Helena Bittencourt; Martins, Wellington de Paula; Bruns, Rafael Frederico; Júnior, Edward Araujo

doi:10.5468/ogs.2016.59.4.303

Cited by 4 publications

(6 citation statements)

References 14 publications

(17 reference statements)

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“…This unusual finding could be related with the small sample size of our study or different characteristics of our population. In a recent study from our group which established reference values for CL measurement between 20 and 24+6 weeks of gestation in 996 singleton pregnancies, CL measurement did not modify significantly with gestational age [ 16 ].…”

Section: Discussionmentioning

confidence: 99%

Second trimester cervical length measurement for prediction spontaneous preterm birth in an unselected risk population

et al. 2017

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ObjectiveTo assess the predictive capacity of cervical length (CL) measurement underwent during the second trimester ultrasound for prediction preterm birth <32, 34, and 37 weeks of gestation in an unselected risk population.MethodsA retrospective cohort study was performed with 751 singleton pregnancies between 20 and 24+6 weeks of gestation. The CL measurement (mm) using the transvaginal route was obtained in a sagittal view and the calipers positioned to measure the linear distance between the triangular area of echodensity at the external os and the internal os. To compare the preterm (<37 weeks) and term births (≥37 weeks), we used unpaired t test. We assessed whether the CL measurement was dependent of gestational age by performing a linear regression and assessing the coefficient of determination (R2). We additionally assessed the accuracy of CL measurement to predict preterm birth by assessing the area under receiver operating characteristics curves with its respective confidence intervals (CIs) 95%.ResultsPreterm birth <37 weeks was found in 13.6% (102/751) of pregnant women. Short cervix (≤25 mm) was found in 2.7% (20/751) of pregnancies. Only 30% (6/20) of pregnant women with short cervix have used progesterone to prevent preterm birth. There was a weak correlation between CL measurement and gestational age at delivery (R2=0.01, P=0.002). Receiver operating characteristics curve analysis of the ability of CL measurement to predict preterm birth <32, 34, and 37 weeks, showed an area under the curve of 0.693 (95% CI, 0.512 to 0.874), 0.472 (95% CI, 0.353 to 0.591), 0.490 (95% CI, 0.426 to 0.555), respectively.ConclusionThere was a weak correlation between CL measurement and gestational age at delivery. In an unselected population, CL measurement screening at 20 to 24+6 weeks of gestation does not seem to be a good predictor of preterm birth.

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Section: Discussionmentioning

confidence: 99%

Second trimester cervical length measurement for prediction spontaneous preterm birth in an unselected risk population

et al. 2017

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“…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.…”

Section: Reference Rangesmentioning

confidence: 99%

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

Filce

Hyett

Sahota

et al. 2019

Aust NZ J Obst Gynaeco

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Background Preterm birth is the leading cause of death in children under the age of five years. Transvaginal cervical length (TVCL) assessment can be used to predict preterm delivery risk at the mid‐trimester scan. To optimise the screening tool, developing and maintaining quality standards is important. Aims To develop an Australian reference range for TVCL at 18.0–21.0 weeks’ gestation, quality standards for measurement and audit mechanisms for ultrasound operators. Materials and Methods A retrospective audit was performed of consecutive patients scanned at 18.0–21.0 weeks’ gestation. Each TVCL measurement ultrasound image was reviewed, and exclusions were made based on a defined set of quality criteria. Fractional polynomial Bayesian methodology was used to establish a reference range. Central tendency, dispersion plots and cumulative sum charts for operators in the original reference range cohort were created. These plots were then applied to a second validation cohort of operators to establish the efficacy of this quality assurance audit tool. Results Median TVCL from 1031 participants was 36.0 mm (interquartile range 32.7–40.0 mm), which was independent of gestational age. The quality audit tool was applied to 15 operators from the reference cohort with a mean cervix length multiple of the median of 1.01 and a mean SD log10 cervix length multiple of the median of 0.06. Of the 22 operators in the validation cohort, 20 (90.9%) demonstrated ideal or acceptable central tendency results, and 19 (86.4%) remained in the appropriate cumulative sum zone. Conclusion An Australian cervix length measurement reference range at 18.0–21.0 weeks’ gestation has been developed along with a validated quality assurance audit tool for ultrasound operators.

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“…4 The most accurate cervical assessment method is the transvaginal ultrasound, which allows adequate observation of the internal and external cervical os and the endocervical canal, with a biometric precision of $ 100%. 5 The morphological and biometric study of the uterine cervix should be performed from the 14 th week of gestation onward because the ultrasonographic differentiation between the cervix and the lower uterine segment using ultrasound becomes difficult before this gestational age. 6 There is no consensus among authors regarding the value of cervical length that is considered short and the associated risk for premature labor, the reported values varying between 20 and 25 mm.…”

Section: Introductionmentioning

confidence: 99%

Assessment of Length of Maternal Cervix between 18 and 24 weeks of Gestation in a Low-Risk Brazilian Population

Andrade

Júnior

et al. 2017

Rev Bras Ginecol Obstet

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Purpose To determine cervical biometry in pregnant women between 18 and 24 weeks of gestation and the ideal mode of measurement of cervical length in cases of curved and straight cervical morphology. Methods The uterine cervices of 752 low-risk pregnant women were assessed using transvaginal ultrasound in a prospective cross-sectional study. In women with straight uterine cervices, cervical biometry was performed in a continuous manner. In women with curved uterine cervices, the biometry was performed using both the continuous and segmented techniques (in segments joining the cervical os). Polynomial regression models were created to assess the correlation between the cervical length and gestational age. The paired Student t-test was used to compare measuring techniques. Results The cervical biometry results did not vary significantly with the gestational age and were best represented by linear regression (R 2 ¼ 0.0075 with the continuous technique, and R 2 ¼ 0.0017 with the segmented technique). Up to the 21 st week of gestation, there was a predominance of curved uterine cervix morphology (58.9%), whereas the straight morphology predominated after this gestational age (54.2%). There was a significant difference between the continuous and the segmented measuring methods in all the assessed gestational ages (p < 0.001). Conclusion Cervical biometry in pregnant women between 18 and 24 weeks was represented by a linear regression, independently of the measuring mode. The ideal measuring technique was the transvaginal ultrasound performed at a gestational age !21 weeks.

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Reference values for the cervical length measurement in the second trimester of pregnancy using the transvaginal ultrasound in a large Brazilian population

Cited by 4 publications

References 14 publications

Second trimester cervical length measurement for prediction spontaneous preterm birth in an unselected risk population

Second trimester cervical length measurement for prediction spontaneous preterm birth in an unselected risk population

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

Assessment of Length of Maternal Cervix between 18 and 24 weeks of Gestation in a Low-Risk Brazilian Population

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