Importance Understanding the relationship between aneuploidy detection on noninvasive prenatal testing (NIPT) and occult maternal malignancies may explain results that are discordant with the fetal karyotype and improve maternal clinical care.
Objective To evaluate massively parallel sequencing data for patterns of copy-number variations that might prospectively identify occult maternal malignancies.
Design, Setting, and Participants Case series identified from 125 426 samples submitted between February 15, 2012, and September 30, 2014, from asymptomatic pregnant women who underwent plasma cell-free DNA sequencing for clinical prenatal aneuploidy screening. Analyses were conducted in a clinical laboratory that performs DNA sequencing. Among the clinical samples, abnormal results were detected in 3757 (3%); these were reported to the ordering physician with recommendations for further evaluation.