What's already known about this topic?

  • Noninvasive prenatal testing for detection of trisomies 21, 18, and 13 is clinically available and is reported to have a false positive rate of 1% or less
  • This technology utilizes massively parallel shotgun sequencing of cell-free DNA, of maternal and placental origin, present in maternal plasma

What does this study add?

  • Unexplained abnormal noninvasive prenatal testing results should prompt consideration of a maternal source of the abnormal cell-free DNA, such as malignancy