Which of the following is a common cause of a false positive on NIPT?

A common cause of a false positive on non-invasive prenatal testing (NIPT) is maternal malignancy. NIPT analyzes free fetal DNA circulating in the maternal blood to assess the risk of certain chromosomal abnormalities in the fetus. However, the presence of maternal malignancies can lead to the shedding of tumor DNA into the maternal bloodstream, which may be mistaken for fetal DNA. This can result in test results that incorrectly suggest an increased risk of chromosomal issues in the fetus, hence generating a false positive.

Maternal age, while an important factor in the overall risk for chromosomal abnormalities, does not directly cause false positives in NIPT results. Follicle-stimulating hormone (FSH) levels are not related to NIPT outcomes, as they are more relevant to assessments of reproductive endocrine function rather than fetal genetic screening. Family history of genetic disorders may influence the decision to conduct NIPT, but it does not lead to false positives in the test itself. Therefore, maternal malignancy stands out as a key factor capable of affecting test accuracy and causing misleading positive results.