NIPT, triple and quad screening: which test, when and what it means

In pregnancy you may hear several “screening tests” mentioned, and it can be confusing which does what. A calm distinction helps: screening tests estimate a chance, while diagnostic tests give a definite answer.

Screening or diagnosis?

A screening test answers the question, “do we need to look more closely?” If the result is lower chance, for most people the process ends there. A higher-chance result is not a diagnosis. A definite answer comes only from diagnostic tests (amniocentesis, chorionic villus sampling).

NIPT (cell-free fetal DNA test)

This looks at small pieces of your baby's DNA circulating in your blood. Only a blood sample is needed and there is no risk to the baby from the test itself. According to international sources the test can be done from about week 10. It offers a highly sensitive screen for certain chromosomal conditions such as Down syndrome, but it is still not a diagnostic test.

In the Turkish Ministry of Health guideline NIPT is not a routine test. Your doctor may suggest it especially when the chance is raised. In Turkey, pricing and conditions can vary between institutions, so ask your doctor or clinic for the current situation.

Triple and quad screening

These blood tests are done in the second trimester.

• Triple test: measures AFP, hCG and estriol.
• Quad test: adds inhibin A to the triple test and is slightly more sensitive.

They are generally done between weeks 15 and 22 on your doctor's advice, if the combined test could not be done. The ministry guideline mentions AFP and the triple/quad test at weeks 16–20. They estimate the chance of Down syndrome and neural tube defects. Again, this is a screening, not a diagnosis.

When does amniocentesis come up?

If a screening result shows a higher chance, if there is a family history, or if something is seen on ultrasound, your doctor may mention amniocentesis for a definite answer. Usually after week 15, a small amount of amniotic fluid is taken with a thin needle under ultrasound guidance. Chorionic villus sampling is done earlier, usually at weeks 10–13.

These procedures carry a small risk of miscarriage. It matters to talk through the risks and benefits with your doctor and decide together. Having it or not is a personal choice and deserves respect.

Which one is right for me?

There is no single answer. Your age, history, combined test result, ultrasound findings, cost and what knowing would mean to you all play a part. Some people prefer routine care only; others want more information.

What you can do

• Before testing, think about what the result would mean to you.
• Ask your doctor what each test can and cannot show.
• Find out about costs and reimbursement in advance.
• Give yourself time and support while you wait.
• Do not let anyone rush your decision.

When to contact your doctor

• If a screening result shows a higher chance
• Bleeding, leaking fluid, fever or severe cramping after an invasive test
• Vaginal bleeding or severe abdominal pain at any time in pregnancy

In a sudden and serious situation, call 112. This article is for information only; decide together with your doctor which tests are right for you.