ArticleBMC pregnancy and childbirth2026
Predicting down syndrome: a comparative evaluation of nasal bone length in mid-trimester pregnancy.
Article in BMC pregnancy and childbirth, 2026. 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
5 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundThis study aimed to evaluate the diagnostic performance of fetal nasal bone length (NBL), the biparietal diameter to nasal bone length ratio (BPD/NBL), and nasal bone length multiples of the median (NBL-MoM) values for Down syndrome (DS) screening between 17 and 25 weeks of gestation in a population-specific cohort.
methodsA retrospective analysis was conducted on fetuses between 17 and 25 gestational weeks. Normative data for NBL and NBL-MoM were generated using gestational age–specific reference medians, and regression equations were established. The NBL, BPD/NBL ratio, and NBL-MoM values were compared between DS and euploid groups. NBL-MoM values were calculated using raw (non-transformed) measurements divided by the expected gestational age–specific median, and euploid status was confirmed by normal postnatal outcomes. Sensitivity, specificity, and likelihood ratios were calculated for various cutoff points.
resultsNBL showed a significant linear correlation with gestational week (R² = 0.31, p < 0.001), while BPD/NBL was independent of gestational age. In DS cases, absence of the nasal bone was observed in 40% of fetuses, compared to 0.03% in controls (sensitivity: 40%, specificity: 100%, LR⁺: 1228). An NBL < 2.5 mm yielded a sensitivity of 49% and specificity of 99.9% (LR⁺: 746). Using the 5th percentile as a cutoff, sensitivity and specificity reached 86% and 98.9%, respectively (LR⁺: 75, LR⁻: 0.15). ABPD/NBL ratio ≥ 9 yielded 93% sensitivity and 97.5% specificity (LR⁺: 37). NBL-MoM values < 0.65 yielded 97% sensitivity and 98% specificity.
conclusionOur findings support the use of population-specific reference ranges for fetal NBL, BPD/NBL ratio, and NBL-MoM values in the second trimester to improve the screening accuracy for Down syndrome. These sonographic markers—particularly NBL < 5th percentile, BPD/NBL ≥ 9, and NBL-MoM < 0.65—may provide valuable, non-invasive indicators to support clinical assessment.
trial registrationThis study was retrospectively registered and authorized by the local Ethics Committee of Ankara University (approval number: 2025/696; date: 03 September 2025).
Indexed as
Identifiers
What OpenQuestion 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 OpenQuestion graph.