What is a normal fetal fraction?

"Fetal fraction" is a term used in non-invasive prenatal testing (NIPT) to measure the amount of fetal DNA present in a maternal blood sample. A normal fetal fraction is typically between 4-10% and indicates a healthy pregnancy with a low risk for chromosomal abnormalities. A fetal fraction below 4% may indicate a higher risk for false negatives or inconclusive results, while a fetal fraction above 10% may indicate a higher risk for false positives. Fetal fraction can vary based on factors such as maternal weight, gestational age, and the specific NIPT technology used. It is important to consult with a healthcare provider to interpret fetal fraction results and determine any necessary follow-up testing.