Evidence map›Paper›PMID 40472075›Full record

ArticleUltrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology2025

Estimating due date in twin pregnancy by second- and third-trimester ultrasound.

K J Rittenhouse, A V Viswanathan, T Pokaprakarn, Y V Sebastião, E Stringer, W Goodnight, J S A Stringer

Abstract read
In one paragraph

Article in Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0cells of the map it votes in
0citing papers in PubMed
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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

7 authors.

K J Rittenhouse *Department of Obstetrics and Gynecology, University of North Carolina School of Medicine, Chapel Hill, NC, USA.ORCID 0000-0002-5571-0793
A V Viswanathan *Department of Obstetrics and Gynecology, University of North Carolina School of Medicine, Chapel Hill, NC, USA.ORCID 0009-0002-6295-0207
T PokaprakarnDepartment of Obstetrics and Gynecology, University of North Carolina School of Medicine, Chapel Hill, NC, USA.
Y V SebastiãoDepartment of Obstetrics and Gynecology, University of North Carolina School of Medicine, Chapel Hill, NC, USA.
E StringerDepartment of Obstetrics and Gynecology, University of North Carolina School of Medicine, Chapel Hill, NC, USA.
W GoodnightDepartment of Obstetrics and Gynecology, University of North Carolina School of Medicine, Chapel Hill, NC, USA.
J S A StringerDepartment of Obstetrics and Gynecology, University of North Carolina School of Medicine, Chapel Hill, NC, USA.

Funding

UNC Global Women’s Health FellowshipT32HD075731 · NICHD · UNIV OF NORTH CAROLINA CHAPEL HILL · PI CHI, BENJAMIN H. · 2013 to 2024
$2.4M
NICHD NIH HHS T32 HD075731NIH HHS T32 HD075731
6 · The paper itself

Abstract

objectiveTo determine the optimal sonographic dating approach for twin gestations presenting to antenatal care beyond the first trimester.

methodsThis was a retrospective cohort study of twin pregnancies receiving care at the University of North Carolina between November 2017 and August 2023 for which the gestational age had been established definitively by first-trimester ultrasound or in-vitro fertilization. All ultrasound studies with complete biometry conducted ≥ 14 weeks' gestation were included. We assessed the accuracy of gestational-age dating using the biometric data of the smaller twin, the larger twin and an average of both cotwins ('average twin'), by comparing estimates with the previously established gestational age ('ground truth').

resultsOur analysis dataset consisted of 596 twin pregnancies. The mean absolute error ± standard error (SE) was 5.8 ± 0.1 days for the smaller twin, 4.4 ± 0.1 days for the average twin and 4.1 ± 0.1 days for the larger twin. The mean error ± SE showed that all three measurements underestimated gestational age compared to the ground truth, with the larger twin exhibiting the least bias (smaller twin, -4.5 ± 0.1 days; average twin, -2.3 ± 0.1 days; larger twin, 0.0 ± 0.1 days). These results persisted when the dataset was restricted to one ultrasound scan per pregnancy and when stratified by chorionicity.

conclusionIn the second and third trimesters, gestational-age dating in twin pregnancies is more accurate and less biased when using the biometry of the larger twin compared with that of the smaller twin or an average of the two twins. © 2025 International Society of Ultrasound in Obstetrics and Gynecology.

Indexed as

Gestational AgePregnancy, TwinUltrasonography, PrenatalAdultBiometryFemaleHumansPregnancyPregnancy Trimester, SecondPregnancy Trimester, ThirdRetrospective Studiesbiometrygestational ageHadlock IVtwin pregnancyultrasound

Identifiers

PMID40472075
PMCPMC12213205

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Registered trials

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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.