Genetic Testing and Pregnancy

We recognize that most pregnancies are low risk and that most babies are born healthy. However, our genetic counselors can provide any interested patient with more information about genetic risk factors. Below is a summary of who may benefit most by testing, as well as some general information on some of the more common tests available.

Please keep in mind that there may be others not listed below that may benefit from testing. Testing is usually not 100% accurate, and it may not be covered by your insurance. You may obtain more detailed information about these diagnoses and many others at

For all moms:

  • There are screening tests which do not provide a diagnosis, but rather a statistical risk of having a baby with a condition such as Down's syndrome.
  • First trimester tests include blood tests (free beta-HCG and PAPP-A) combined with an ultrasound to evaluate some of baby's characteristics.
  • Second trimester testing includes the maternal serum alpha-fetoprotein (AFP) quad blood test and the 20-week ultrasound/anomaly scan.

Age > 35 for moms, age > 45 for dads (younger if you have twins):

  • Increased risk for Down's syndrome, Trisomy 18 or 13, or other extra chromosomes. 
  • An optional first trimester test is needle sampling of part of the placenta (CVS); or performing an amniocentesis during the second trimester.

Caucasians, especially those of Northern European descent:

  • Increased risk for Cystic Fibrosis (CF) - 1 in 29 is a carrier, 1 in 3,300 will be diagnosed with CF.
  • Carrier testing is by cheek swab or blood testing at any time.

African Americans:

  • Increased risk for sickle cell disease.
  • Testing is by blood test, typically done at the first prenatal visit.

Ashkenazi Jews (Eastern European descent):

  • Increased risk (1 in 30) for Tay-Sachs, Gaucher, Canavan Disease, or Familial Dysautonomia.
  • Testing is by blood test at any time, although accuracy is best prior to conception.
  • The American College of Obstetricians and Gynecologists recommends screening only for CF, Tay Sachs, and Canavan disease in those who have Ashkenazi Jewish ancestry.

Unplanned pregnancy (due to no pre-pregnancy folic acid supplementation):

  • Increased risk for neural tube defects (NTD), e.g. spina bifida and anencephaly.
  • Risk is higher if there is a family history of NTD.
  • Testing includes an AFP blood test, needle sampling of the amniotic fluid (amniocentesis), or ultrasound in the second trimester.