Nipt test and low fetal fraction

[AnnieStar12]

I got my results from the nipT which thankfully came back low risk for everything. But the fetal fraction is only 3%. I had bloods drawn at 10+1 and am a bit concerned about what this low level means. I can’t seem to get answers from google and didn’t do the tests via a clinic but with a blood test company (concepto) so no doctor on hand to answer my questions.

Does anyone know if this indicates anything is wrong and/or does it make the test results less valid?

From medlineplus.gov/genetics/understanding/testing/nipt/#:~:text=The%20proportion%20of%20cfDNA%20in,or%20a%20false%20negative%20result.

"There must be enough fetal cfDNA in the mother’s bloodstream to be able to identify fetal chromosome abnormalities. The proportion of cfDNA in maternal blood that comes from the placenta is known as the fetal fraction. Generally, the fetal fraction must be above 4 percent, which typically occurs around the tenth week of pregnancy. Low fetal fractions can lead to an inability to perform the test or a false negative result. Reasons for low fetal fractions include testing too early in the pregnancy, sampling errors, maternal obesity, and fetal abnormality."

Sounds like your chance of a false negative may be slightly higher than normal as the fetal fraction was only 3%. Assuming you live in the UK you'll get your combined screening test at your 12 week scan, so could wait to see what that says, or if you're concerned you could retest