Prenatal aneuploidy testing comparison table
Select prenatal screening and diagnostic testing options for Trisomy 21 and other fetal aneuploidies
|Cell-free DNA screening||First trimester screening||Second trimester serum screening||CVS and Amniocentesis|
|When||9-10 weeks until term||10-14 weeks||15-22 weeks||CVS: 10-13 weeks
Amniocentesis: 15-16 weeks and over
|How performed||Maternal blood||Maternal blood + ultrasound||Maternal blood||Invasive procedure|
|Risks||None||None||None||Risks of miscarriage
|T21 detection rate||>99%||85%||81%||>99%|
|T21 False-positive rate||<1%||2.5-5%||5%||<1%|
|Other conditions included and detection rates||T18 98%
Sex chromosome aneuploidy, Trisomy 22 and 16,
Microdeletion/duplication conditions - uncertain
|All aneuploidies >99%
OFD (Amniocentesis) >95%
Other genetic conditions if indicated – depends on condition
|Unreportable/no call rate||<1%-5%||<1%||<1%||1-3%|
|Normal||Screen for OFD in 2nd trimester||Screen for OFD in 2nd trimester||None||Screen for OFD in 2nd trimester if CVS performed|
|Unreportable/no-call||CVS/amniocentesis or consider repeat cfDNA||Redraw||Redraw||Repeat or cfDNA|
CVS=Chorionic villus sampling; OFD=Open fetal defect; T13=Trisomy 13; T18=Trisomy 18; T21=Trisomy 21; US = Ultrasound
ACOG and SMFM, Practice Bulletin #226 Screening for Fetal Chromosome Abnormalities. 2020.
Fairbrother, G., et al., Prenatal screening for fetal aneuploidies with cell-free DNA in the general pregnancy population: a cost-effectiveness analysis. J Matern Fetal Neonatal Med, 2016; 29(7): 1160-4.
Rose NC, Barrie ES, Malinowski J, Jenkins GP, McClain MR, LaGrave D, Leung ML; ACMG Professional Practice and Guidelines Committee. Systematic evidence-based review: The application of noninvasive prenatal screening using cell-free DNA in general-risk pregnancies. Genet Med. 2022 May 10:S1098-3600(22)00714-6.
SMFM, Consult Series #36: Prenatal aneuploidy screening using cell-free DNA. Am J Obstet Gynecol, 2015; 212(6): 711-6.
Updated October 2022