Tests related to pregnancy

You can screen a pregnancy for Down’s syndrome with a maternal blood sample.

To learn more about pregnancy related screening and genetic counseling, read Making Sense of Your Genes: A Guide to Genetic Counseling.


What Are Tests Related to Pregnancy?

Pregnancy related testing is done before or during pregnancy. There is a lot of information you can find out about your health and an unborn baby’s health through these tests. Pregnancy related testing can find:

  • Genetic conditions before a child is born
  • Risks of genetic conditions for your future children
  • Genetic conditions in the mother discovered while checking for genetic conditions in the baby

Who Should Think about Pregnancy Related Testing?

You should speak with your healthcare provider about your risks before getting any testing. 
People in the following categories should think about pregnancy related testing: 

  • Women who are pregnant, or planning to be pregnant, who are 35 and older
  • Families with a history of a genetic condition
  • Families who have had multiple pregnancy losses (including babies who were born but later died)
  • Families whose prenatal screening (such as an ultrasound or blood test) shows the baby is at increased risk for having a genetic condition or birth defect
  • Families who are worried that their jobs, lifestyles, or medical histories may pose an increased risk to the baby (some examples are radiation at work, some medicines, illegal drugs, chemicals, or infections)

When Do You Have Pregnancy Related Testing?

There are two general kinds of pregnancy related testing:

1. Pre-conception genetic testing

Pre-conception testing happens before you are pregnant. It checks if you and/or your partner are carriers for certain genetic conditions. If you both are carriers for the same condition, you have a chance of having children with that disorder. Some places also have testing for conditions that a woman can pass on to her sons. A genetic counselor can explain these risks to you. See our discussion of carrier screening for more information.

2. Pre-implantation genetic testing

Pre-Implantation genetic testing also happens before you are pregnant, but embryos are tested instead of the parents.  Eggs from the mother-to-be are fertilized in a test tube with sperm from the father-to-be.  This process is called in-vitro fertilization, or IVF.  The resulting embryos are then tested for increased risk of genetic conditions. Other traits may also be tested as well, such as the sex of the embryo. After testing, embryos that are found to have lower risk of genetic health conditions are placed or implanted into the mother’s womb so that she may become pregnant.

A physician or genetic counselor may suggest pre-implantation genetic testing if,

  • One or both parents have undergone pre-conception testing and are found to be a carrier for a genetic condition.
  • A woman has had significant trouble becoming pregnant
  • A woman has a recurrent history of miscarriages 

3. Prenatal genetic testing

Prenatal testing happens while you are pregnant. It looks for genetic conditions before the baby is born. Your healthcare provider may suggest prenatal testing if:

  • An ultrasound shows a possible genetic condition or birth defect
  • Results of a screening blood test show a possible problem in the baby

A genetic counselor can provide information about prenatal testing and results such as:

  • What may happen with the pregnancy if there is a genetic condition
  • Things that may happen during delivery
  • How to prepare for having a baby with a genetic condition
  • Problems that the baby may have
  • Possible risks of continuing with the pregnancy
  • Possible risks in future pregnancies

Types of prenatal tests available may depend on: 

  • how far along the pregnancy is, and
  • the conditions that your doctor wants to check for in the baby.