ArticlePrenatal diagnosis2025
Diurnal Effects on the Fraction of Fetal Cell-Free DNA in Maternal Plasma.
Article in Prenatal diagnosis, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.
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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.
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Who cites it
1 citing paper in PubMed.
- Clinical Implications and Limitations of Noninvasive Prenatal Testing for Detecting Fetal Copy Number Variations: A Multicenter Study in Shaanxi Province, China.Medical science monitor : international medical journal of experimental and clinical research · 2026Observational
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Authors and funding
3 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectiveThe discovery of fetal cell-free DNA (cfDNA) has revolutionized prenatal diagnostics through non-invasive prenatal testing (NIPT), which depends on accurately measuring the fetal fraction (FF) in maternal plasma. While FF is known to be influenced by maternal and fetal factors, the impact of intraday rhythms remains unclear. This study investigated whether FF varies based on blood draw timing.
methodsData from 2519 euploid singleton pregnancies undergoing NIPT were analyzed. Key variables included maternal age, BMI, gestational age, fetal sex, and blood draw timing (06:50-21:00). FF was measured using the Harmony Prenatal IVD Test. Multiple linear regression identified independent predictors of FF, while intraday variation was assessed using Mann-Whitney U tests and boxplots.
resultsFF showed a significant positive relationship with blood draw timing (β = 0.00176 per hour, p < 0.005), with afternoon values approximately 10% higher than morning values (∼0.01 difference). Other predictors included BMI (negative), gestational age (positive), and fetal sex (higher in females). Blood draw timing appeared to be a stronger predictor of FF than gestational age or fetal sex, second only to BMI.
conclusionThis novel finding demonstrates diurnal variation in FF, suggesting that optimizing blood draw timing could improve NIPT accuracy, particularly in borderline cases. Further research is needed to confirm the clinical implications.
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