unc cell free dna ppv npv positive predictive value sensitivity specificity trisomy 21 trisomy 13 trisomy 18 Harmony Materniti 21 Panorama Verifi Down Syndrome Edwards syndrome Patau syndrome
Aneuploidy Screening
NIPT CVS amniocentesis quad screen genetic sonogram genetics chromosomal abnormalities
Hemoglobinopathy Screening
Estimation of Gestational Age (EGA)
EGA ultrasound crown rump length combined fetal biometry ART-derived EGA IVF Ultrasound methods of confirmation of LMP-based EDC or to determine EDC
