P856: Counseling and management of a maternal diagnosis of mosaic trisomy 8 ascertained through prenatal cell-free DNA screening

The patient’s gestational age precluded maternal serum screening for aneuploidy; therefore, the option of an alternate cfDNA through a single nucleotide variant-based (SNV-based) NGS platform focused on common aneuploidy detection was offered to the patient. The risks, benefits, and limitations of parental chromosome analysis, alternate cfDNA, and diagnostic fetal chromosome analysis were discussed. The patient elected personal cytogenetic analysis and the alternate cfDNA option. The patient declined fetal chromosome analysis through amniocentesis because of the risk for preterm labor.