Evidence map›Paper›PMID 41499517›Full record

Observational studyUltrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology2026

Reference charts for first-trimester placental three-dimensional fractional moving blood volume derived using OxNNet.

S Mathewlynn, L N Starck, Y Yin, M Soltaninejad, M Swinburne, K H Nicolaides, A Syngelaki, A G Contreras, S Bigiotti, E-M Woess and 2 more

Abstract readObservational Study
In one paragraph

Observational study in Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

12 authors.

S MathewlynnNuffield Department of Women's and Reproductive Health, University of Oxford, Oxford, UK.ORCID 0000-0003-1609-3654
L N StarckFetal Medicine Research Institute, King's College Hospital, London, UK.
Y YinNuffield Department of Women's and Reproductive Health, University of Oxford, Oxford, UK.
M SoltaninejadNuffield Department of Women's and Reproductive Health, University of Oxford, Oxford, UK.ORCID 0000-0002-9889-4369
M SwinburneNuffield Department of Women's and Reproductive Health, University of Oxford, Oxford, UK.ORCID 0009-0000-3979-6761
K H NicolaidesFetal Medicine Research Institute, King's College Hospital, London, UK.ORCID 0000-0003-1266-0711
A SyngelakiFetal Medicine Research Institute, King's College Hospital, London, UK.ORCID 0000-0001-5856-6072
A G ContrerasFetal Medicine Research Institute, King's College Hospital, London, UK.
S BigiottiFetal Medicine Research Institute, King's College Hospital, London, UK.
E-M WoessFetal Medicine Research Institute, King's College Hospital, London, UK.
S GerryCentre for Statistics in Medicine, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK.
S CollinsNuffield Department of Women's and Reproductive Health, University of Oxford, Oxford, UK.ORCID 0000-0002-0648-7433

Funding

National Institute for Health Research and NHSX AWARD02497
6 · The paper itself

Abstract

objectiveTo establish a comprehensive reference range for first-trimester placental three-dimensional (3D) single-vessel fractional moving blood volume (svFMBV) using the OxNNet toolkit, based on values observed in healthy pregnancies.

methodsThis study utilized data from the First-trimester Placental Ultrasound (FirstPLUS) study, a longitudinal observational cohort study conducted between March and November 2022 at King's College Hospital, London, UK. Participants underwent 3D ultrasound assessment of the placenta, including power Doppler imaging, during routine first-trimester screening. The OxNNet toolkit was used for automated placental segmentation and 3D-svFMBV calculation. Quality control was performed in three stages to ensure image completeness and segmentation accuracy. Quantile regression and lambda-mu-sigma (LMS) modeling were used to construct reference charts for 3D-svFMBV. Model fit was assessed using the Akaike information criterion, and centile curves were constructed.

resultsThe final cohort comprised 2547 cases. Visual assessment of histograms and quantile-quantile plots revealed positive skew in 3D-svFMBV determined at five specific locations within the uteroplacental vasculature. LMS modeling provided the best fit for constructing centile charts, with the Box-Cox Power Exponential original distribution used in most cases. The resulting centile charts demonstrated close agreement between predicted and observed centiles, with minimal deviation across all target centiles.

conclusionsThis study provides novel reference ranges for first-trimester placental 3D-svFMBV at five locations within the uteroplacental vasculature. These findings offer a valuable foundation for future research into placental function and pregnancy outcome. © 2026 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Indexed as

Blood VolumeImaging, Three-DimensionalPlacentaPregnancy Trimester, FirstUltrasonography, PrenatalAdultFemaleHumansLongitudinal StudiesPregnancyReference ValuesUltrasonography, Dopplerbiomarkerdeep learningfetal growth restrictionfirst‐trimester pregnancyfractional moving blood volumeplacentapower Doppler ultrasonographypre‐eclampsiaprenatal ultrasonographyreference values

Identifiers

PMID41499517
PMCPMC12865523

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.