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Prenatal Testing and Diagnosis

Prenatal Testing and Diagnosis

When routine prenatal tests detect a possible health issue with your unborn child, you might want to consider more advanced testing to be sure of the diagnosis.

This information can help your health care team manage fetal conditions during your pregnancy, or investigate possible in-utero treatment options.

It also means that you and your health care team can better prepare for the delivery of a child with a health problem that might need intervention immediately upon birth.

Maternal-Fetal Medicine Services offer a full spectrum of both screening and diagnostic tests to evaluate the health of the fetus, placenta, umbilical cord and uterine environment and predict the likelihood of genetic problems.

Screening Tests

Screening tests are less invasive, but only predict the likelihood of a problem.

  • A nuchal translucency (NT) screening is typically included in the 11 to 14 week ultrasound. It can estimate the baby's risk for Down Syndrome.
  • A blood test called the first trimester screen looks for biochemical markers of Down Syndrome, so results might be "a 1 in 600 chance of Down Syndrome."
  • Maternal serum AFP (which measures a protein called alpha-fetoprotein in the mother's blood) screens for neural tube defects such as spina bifida.
  • Ultrasound is used to estimate the age or size of a baby, to look for birth defects or observe a baby's activity and environment to evaluate well-being. Evaluations of the placenta, uterus and cervix also contribute information about possible risks to the pregnancy.

Diagnostic Tests

Diagnostic tests are more invasive, but can actually confirm a problem suspected after screening.

  • Chorionic villus sampling extracts a few cells from the placenta to be analyzed for genetic conditions.
  • Amniocentesis takes a sample of amniotic fluid to be analyzed for chromosome abnormalities like Down Syndrome or spina bifida or other genetic diseases.
  • Percutaneous umbilical cord blood sampling sampling withdraws a blood sample from the umbilical cord while the fetus is still in the uterus for rapid chromosome analysis of the risk for certain blood disorders.


Before any tests, we will thoroughly discuss the potential risks, benefits and possible fetal conditions with you.

The Decision is Yours

Ultimately, the decision to pursue prenatal testing is up to you. You should discuss the risks and benefits with your health care provider. You might also meet with our genetic counselor for a more thorough evaluation.

Our genetic counselor can help you understand:

  • The odds of your baby developing a particular condition
  • How the condition would impact your baby's life, including your baby's physical and mental development and quality of life
  • Possible treatment options, either during pregnancy or after birth

Taking the time to evaluate your options will help you make the best decision for you and your baby.

If you would like to schedule a testing appointment, please call us at 425.899.2200.

For more information, and to best prepare you for a discussion with your provider, please first watch this video, created by our own genetic counselors.

Maternal-Fetal Medicine Services
EvergreenHealth Medical Center  - Tan 240                  
425.899.2200

Appointments are available Monday-Friday from 7:30am-4pm.