In a recent study, published in February 2023 in Prenatal Diagnosis, we investigated in collaboration with Prof. Kagan (University Women’s Hospital Tuebingen) the correlation between the screen-positive rate and the fetal fraction (proportion of cell-free fetal DNA) when screening for microdeletion 22q11.2 (DiGeorge syndrome).
We analyzed own data from more than 50,000 singleton pregnancies.
The results of our study show a significant inverse correlation between the fetal fraction and the screen-positive rate.
In samples with a fetal fraction below 11%, the positive rate was 0.93%, while in samples with a fetal fraction above 11% it was only 0.13%.
You can view the entire study here.