Methods for cervical volume measurements

Research output: Contribution to journalMeeting Abstractpeer-review


We aimed to compare three methods for cervical volume measurements. There is a known correlation between loop electrosurgical excision procedures and the risk of preterm birth. Authors hypothesise that in the future pre-pregnancy cervical regeneration level after LEEP procedures could be used for risk stratification for preterm birth. Therefore, available and easily reproducible methods are needed to study cervical volume and regeneration in clinical practice.

Cervical two- and three-dimensional (3D) measurements were obtained by pre-defined criteria during a gynecological ultrasound and assessed by two examiners in a blinded manner from the archive. Measurements included: cervical length (CL), cervical anteroposterior (AP), and longitudinal (LL) diameters. Cervical volume was measured three times by 3D VOCAL (Virtual Organ Computer-Aided Analysis) software (VVOCAL), by cylinder formula VFORMULA = 3.14×[AP+LL)/4]2 ×Length CERVIX and devices inbuilt generic volume formula VGENERIC =  length x AP X LL. For inter method and interobserver agreement VCYLINDER FORMULA, VGENERIC formula use was compared to VVOCAL, as a gold standard. ICC (interclass correlation coefficient) was calculated, using a two-way mixed-effects model in SPSS.

We included 100 participants, average age 34,21 years. Average cervical VGENERIC =16.78 cm3, VVOCAL 25.05 cm3, VCYLINDER FORMULA 25.61 cm3. Generic formula underestimated cervical volume by 49% compared to VCYLINDER FORMULA, therefore VGENERIC measurements were excluded from further analysis. Interobserver coefficient (ICC) VVOCAL= 0.92 (p < .00, CI 0.87-0.92), VCYLINDER FORMULA=0.93, (p < .00, CI 0.89-0.95) was excellent. Intermethod ICC between VVOCAL and VCYLINDER FORMULA =0.94 (p < .00, CI 0.91-0.96).

Excellent intermethod agreement suggests that cylinder formula use is compatible with VOCAL cervical volume measurements. Excellent interobserver shows that measurements are reproducible between observers. Cervical volume measurement by cylinder formula could be a cost-effective alternative to VOCAL software use, implicating its wider use in practice.
Original languageEnglish
Pages (from-to)128
JournalUltrasound in Obstetrics and Gynecology
Issue numberSuppl.1
Publication statusPublished - 14 Oct 2021
Event31st World Congress on Ultrasound in Obstetrics and Gynecology - Virtual
Duration: 15 Oct 202118 Oct 2021
Conference number: 31

Field of Science*

  • 3.2 Clinical medicine

Publication Type*

  • 3.4. Other publications in conference proceedings (including local)


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