Incidental finding of maternal malignancy in an unusual non‐invasive prenatal test and a review of similar cases

Abstract We present a clinical case where a complex abnormal non‐invasive prenatal test (NIPT) result in a research project revealed carcinoma of the breast in the pregnant woman. Furthermore, the NIPT result did not demonstrate the same fetal chromosomal aberration as the chorion villus sample. A literature search for similar cases was performed identifying 43 unique cases, where abnormal NIPT results were related to maternal malignancy. Malignancy is a rare but important cause of complex abnormal non‐invasive prenatal test (NIPT) results and should be considered when fetal karyotype and abnormal NIPT results are discordant. Furthermore, a follow‐up invasive sample is essential for correct fetal diagnosis when abnormal NIPT results are found.