Protocol for the e-POWUS Project: multicentre blinded-randomised controlled trial of ultrasound speed choice to improve sonography quality in pregnant women with obesity

Abstract

Introduction: During pregnancy, maternal obesity increases the risk of fetal abnormalities. Despite advances in ultrasound imaging, the assessment of fetal anatomy is less thorough among these women. Currently, the construction of ultrasound images uses a conventional ultrasound propagation velocity (1540 m/s), which does not correspond to the slower speed of propagation in fat tissue.The main objective of this randomised study is to compare the completeness of fetal ultrasonography according to whether the operator could choose the ultrasound velocity (1420, 1480 or 1540 m/s) or was required to apply the 1540 m/s velocity.

Methods and analysis: This randomised trial is an impact study to compare a diagnostic innovation with the reference technique. The trial inclusion criteria require that a pregnant woman with obesity be undergoing a fetal morphology examination by ultrasound from 20+0 to 25+0 gestational weeks.Randomisation will allocate women into two groups. The first will be the 'modulable speed' group, in which operators can choose the speed of ultrasound propagation to be considered for the morphological analysis: 1420, 1480 or 1540 m/s. In the second 'conventional speed' group, operators will perform the morphological examination with the ultrasound speed fixed at 1540 m/s. The adjudication committee, two independent experts, will validate the completeness of each examination and the quality of the images.

Ethics and dissemination: This research protocol does not change the standard management. The only possible impact is an improvement of the ultrasound examination by improving the quality of the image and the completeness of morphological examination. The Agence du Médicament et produits de santé approved this study (2018-A03478-47). The anonymised data will be available on request from the principal investigator. Results will be reported in peer-reviewed journals and at scientific meetings.

Trial registration number: ClinicalTrials.gov (http://www.clinicaltrials.gov) Registry (NCT04212234).

Keywords: prenatal diagnosis; ultrasonography; ultrasound.

Conflict of interest statement

Competing interests: None declared.

© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.

Figures

Figure 1

Study design. BMI, body mass index; GW, gestational weeks; US, ultrasound.

Figure 2

The ultrasound images recommended by CNEOF (A) for the second trimester ultrasound examination; (B) for the third trimester ultrasound examination. CNEOF, French National Conference of Obstetric and Fetal Ultrasound.

Figure 3

Time schedule of participant enrolment, interventions and visits.

Figure 4

Standardised measurements taken halfway between the umbilicus and the pubis, performed during the first ultrasound (US) appointment of the second and of the third trimester: adipose tissue thickness (ATT)—distance between probe and muscle fascia; distance between probe and amniotic fluid (PAF). Organ-specific measurements for each ultrasound image recommended by the CNEOF: organ-specific scanning plane (ssp) ATT; ssp distance between the probe and the target organ (PTO). CNEOF, French National Conference of Obstetric and Fetal Ultrasound.