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Updated: May 18, 2026
High Frequency Ultrasound for the Analysis of Fetal and Placental Development In Vivo
Published on: November 8, 2018
Accurate and robust quantification of circulating fetal and total DNA in maternal plasma from 5 to 41 weeks of
Lyndsey Birch1, Claire A English, Keelin O'Donoghue
1BioAnalytical Innovation Team, LGC Ltd., Teddington, United Kingdom.
Background:
Detection of fetal DNA in maternal plasma is achievable at 5 weeks of gestation, but few large-scale studies have reported circulating fetal and maternal DNA across all trimesters.
Methods:
Blood samples were collected from 201 women between 5 and 41 weeks of pregnancy. Quantitative PCR was used to assess total and fetal DNA concentrations, and allelic discrimination analysis was investigated as a route to detecting specifically fetal DNA.
Results:
Male fetuses were detectable from 5 weeks amenorrhea with increasing fetal DNA concentrations across gestation. The sensitivity of fetal male gender determination in pregnancies with live birth confirmation was 99%, with 100% specificity. Total DNA concentrations did not correlate with gestational age, but appeared slightly higher in the first and third trimesters than in mid-pregnancy. Analysis of short tandem repeats demonstrated that significant improvements in the detection limit are required for specific detection of fetal DNA.
Conclusions:
The high sensitivity of PCR-based detection, together with quantification provided by real-time DNA analysis, has clear potential for clinical application in noninvasive prenatal diagnosis. However, accurate quantification using best-fit data analysis, standardization of methods, and performance control indicators are necessary for robust routine noninvasive diagnostics.
