NIPT results with low fetal fraction

My OB said I could get the Maternit21 test if I was interested because I will be 35 one week before baby is due, so I did it. The first blood draw (at 12 weeks) came back inconclusive due to low fetal fraction (results actually say fetal fraction is less than 3%).

I went for the re-draw 2 weeks later, and the results to that was all good and baby is a girl, but the fetal fraction was only 3%! My OB was surprised they gave results with such a low fetal fraction, but she is choosing to trust them. I’m not so sure!

I go for my anatomy scan in 2 weeks to confirm, but I can’t help worrying that I can’t trust these NIPT results! I am a very scientific person and I read a peer-reviewed research article about how no NIPT company should give conclusive results for fetal fraction less than 3.5% because it just isn’t accurate.

Has anyone been in the same boat? Have you ever gotten NIPT results with a fetal fraction of 3%, and if so, were the results accurate?