Prenatal Genetic Screening

Take a look at the brief description of these common genetic screening methods to get a snapshot of information. Our physicians can provide a consult to discuss these in more detail.

Non-Invasive Methods
  • Early Screen – first trimester
    • first trimester prenatal screening and ultrasound examination
    • blood test combined with 11-13 week ultrasound to determine chance of having a baby with Down syndrome, trisomy 13 or trisomy 18
    • measures proteins: free Beta human chorionic gonadotropin and PAPP-A
    • has false positives and false negatives
  • Cystic Fibrosis (CF) Carrier Screening - anytime
    • CF is a genetically inherited disease
    • CF carrier screen tells you your risk for carrying an altered gene
  • Quad Screen - 15-20 weeks
    • maternal blood test which measures proteins: alpha fetoprotein (AFP), human chorionic gonadotropin (hCG), estriol and inhibin A
    • screens primarily for abnormalities in the brain and spinal cord, Down syndrome and trisomy 18
    • has false positives and false negatives
    • may lead to further testing
Invasive Methods
  • Chorionic Villus Sampling – 9-14 weeks
    • procedure performed in the first trimester which removes cells from the placenta through a needle
    • determines chromosomal makeup of baby
  • Amniocentesis – more than 15 weeks
    • procedure performed under ultrasound guidance in the second trimester which removes amniotic fluid from around the baby through a needle
    • determines chromosomal makeup of baby