Prenatal Testing: Labs and Genetic Testing

Prenatal lab and genetic testing monitor your health and your baby's development during pregnancy.  

These tests can help detect genetic conditions and identify medical issues early. However, they may also raise emotional and ethical concerns about what to do with the information.

Your health care provider will recommend tests based on your preferences, medical and family history, and stage of pregnancy.

In early pregnancy, you may have:

• Blood tests to check your health and blood type and look for infections like HIV or hepatitis.
• A urine test to look for signs of infection, diabetes, or other issues.

If you choose to have genetic screening, your options include:

• Cell-free DNA (cfDNA) or noninvasive prenatal testing (NIPT), which analyzes your baby’s DNA in your bloodstream to detect genetic conditions and sex.
• A genetic carrier screening test, which checks whether you carry genes for inherited diseases like cystic fibrosis, sickle cell anemia, or spinal muscular atrophy.

Your provider may also recommend chorionic villus sampling (CVS), which tests the placental tissue if there are concerns from earlier screenings.

Your provider may recommend:

• AFP, a blood test that checks for conditions like Down syndrome and neural tube defects.
• A glucose screening test to check for gestational diabetes.
• Amniocentesis, which tests the amniotic fluid if there are concerns from earlier screenings.

In the later stages of pregnancy, you may have:

• A group B strep test, which involves swabbing the vaginal and rectal areas to check for bacteria that requires antibiotics during labor.
• Another blood test to check for anemia, infections, and healthy blood clotting for delivery.
• Another urine test for infections and protein levels if preeclampsia is a concern.

• Drink plenty of water before your blood draws — it can make them easier.
• For most blood and urine tests, you don’t need to do anything else beforehand.
• You may need to fast before your glucose test.

It's natural to feel anxious about these tests, but they're essential for ensuring a healthy pregnancy.

Normal results mean your tests didn’t find any signs of concern.

Abnormal results don’t necessarily mean something is wrong but might mean more tests are needed.

Your provider will explain any positive genetic tests and help you understand the chances of certain conditions.