Prenatal Diagnosis Program

Understanding Prenatal Tests

Prenatal tests are done for various reasons. Some tests occur at the start of your pregnancy to evaluate your health, but they do not provide any information about your baby. Most of these routine lab tests screen for infectious or sexually transmitted diseases or pre-existing conditions that could make yours a high-risk pregnancy. You and your doctor can take protective steps when you know these risk factors early. Examples of routine tests your obstetrician may order are:

• Blood type
• Complete blood count
• Hepatitis B and hepatitis C
• Human immunodeficiency virus (HIV)
• Rubella
• Sexually transmitted disease (STD)
• Tuberculosis
• Urinalysis
• Urine culture

Another type of prenatal testing is genetic screening, which checks for conditions that could affect the health of your unborn child. According to the American College of Obstetricians and Gynecologists, all pregnant women should be offered prenatal genetic screening. These tests are often painless and pose no risk to you or your child. The most common prenatal tests used for genetic screening are:

• Cell-free fetal DNA test for Down syndrome, Trisomy 18 and Trisomy 13
• Carrier screening for cystic fibrosis, spinal muscular atrophy, sickle cell anemia and other conditions
• Maternal serum AFP for open neural tube defects, such as spina bifida
• Ultrasound

Although a prenatal screening test can suggest a health condition in your unborn child, only more advanced testing can confirm it. Prenatal diagnostic tests are a higher tier of tests designed to pinpoint specific health concerns. For example:

• Chorionic villus sampling takes cells from the placenta and analyzes the chromosomes or DNA to confirm certain genetic conditions in the baby.
• Amniocentesis analyzes amniotic fluid to diagnose certain genetic conditions and confirm brain or spinal cord defects.
• Percutaneous umbilical blood sampling analyzes a sample of your unborn baby’s blood to identify fetal anemia.

These tests tend to be more invasive, so they carry a slight risk to your unborn child. Our genetic counselors are available to explain the risks, benefits and limitations of these testing options.

Who should consider diagnostic genetic testing?

• Partners who have a family history of a birth defect or genetic condition
• If you are 35 or older at the time of delivery
• If you receive an abnormal serum screening that suggests certain birth defects

The Prenatal Diagnosis Program at Riley at IU Health offers highly skilled specialists in prenatal diagnosis. Our experts can help:

• Manage your pregnancy
• Determine the likely outcome of your pregnancy
• Plan for possible birth complications
• Anticipate health problems in your newborn
• Identify conditions that have implications for future pregnancies

Maternal-fetal physicians and genetic counselors evaluate pregnancies where babies may be at risk for birth defects or health conditions. Our specialists use the latest screening and diagnostic tests to detect areas of concern. From the results, we can recommend plans for your pregnancy and delivery so you can make informed healthcare decisions. If you come to us through a referral from your obstetrician, we maintain an open line of communication to keep your physician informed.