ArticleBJOG : an international journal of obstetrics and gynaecology2025
The Impact of Dating Twin Pregnancy by the Larger, Smaller or Mean Twin Crown-Rump Length: A Retrospective Cohort Study.
Article in BJOG : an international journal of obstetrics and gynaecology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
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.
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.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
4 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectiveTo evaluate the impact of twin dating by ultrasound-measured crown-rump length (CRL) of the larger (CRL-L), smaller (CRL-S) or mean twin measurement (CRL-M) on the rates of preterm birth (PTB) and detection of small for gestational age (SGA) births.
designA retrospective cohort study.
settingA tertiary fetal medicine centre (London, UK). POPULATION OR SAMPLE: All twin pregnancies between 1998 and 2023 who underwent first trimester CRL ultrasound assessment and fetal growth assessment.
methodsData collection included CRL measurement, estimated fetal weight (EFW), pregnancy outcome and birthweight (BW) for each twin. Pregnancies were retrospectively re-dated by CRL-S, CRL-L and CRL-M.
main outcome measuresSGA < 10th centile and extreme PTB rates (< 28 weeks).
resultsIn the 1129 twin pregnancies, median CRL-S was 61 mm (interquartile range [IQR]: 56.0-66.0) and CRL-L was 63 mm (IQR: 58.4-68.9) with a mean discordance of 4.0%. Prenatal SGA diagnosis occurred in 19.8% and 23.1% of smaller twins when dated by CRL-S and CRL-L, respectively. When pregnancies were dated by CRL-M versus CRL-S or CRL-L, there was no difference in prenatal SGA diagnosis (p = 0.275 and p = 0.419); SGA at birth (p = 0.132 and p = 0.325); or extreme PTB (p = > 0.999 and p = 0.765 respectively).
conclusionsDating by the smaller, larger or mean twin CRL does not significantly alter rates of extreme preterm birth, SGA detection or SGA birth. Dating by the mean twin CRL reduces stigmatisation of the smaller twin and retains the utility of accurate gestational age assessment without impacting clinical outcomes.
Indexed as
Identifiers
What Socratic holds
Registered trials
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 Socratic graph.