NIPT - Non-Invasive Prenatal Testing
NIPT (Non-Invasive Prenatal Testing) is currently the most reliable non-invasive test for prenatal genetic screening of the fetus.
Prenatal screening has made tremendous advances in recent years. NIPT is perhaps the most important development: a simple blood test that provides answers with a level of reliability that, until recently, required invasive procedures—and with zero risk to the pregnancy.
Today, from the 10th week of pregnancy, we can screen with reliability reaching 99% for the most common chromosomal abnormalities, simply from a blood sample taken from the mother. In some cases, the test may be performed even earlier, always after evaluation and with the physician’s agreement.
What is NIPT and how does it work?
During pregnancy, small fragments of fetal DNA circulate freely in the mother’s bloodstream. From the 10th week of pregnancy, their concentration is high enough for us to analyze them.
By analyzing this fetal DNA from a simple blood sample taken from the mother, we can screen with very high reliability for chromosomal abnormalities in the fetus, without any contact with the uterus, placenta, or fetus.
What does NIPT detect?
Depending on the type of test, NIPT screens for:
The three most common trisomies:
- Trisomy 21 — Down syndrome (sensitivity >99%)
- Trisomy 18 — Edwards syndrome
- Trisomy 13 — Patau syndrome
Sex chromosome abnormalities, such as Turner syndrome and Klinefelter syndrome.
Microdeletions in expanded panels—rarer chromosomal abnormalities such as DiGeorge syndrome.
Fetal sex—if the couple wishes to know, from as early as the 10th week.
When is NIPT done?
From the 10th week of pregnancy onward—earlier than any other highly reliable screening test. There is no upper gestational age limit.
It is most commonly done when:
- The first-trimester combined screening showed increased risk
- The couple wants a highly reliable result from the outset, without waiting
- The mother is over 35 years old
- There is a history of chromosomal abnormality in a previous pregnancy
NIPT or amniocentesis?
This is the question almost all couples ask when prenatal screening shows something that needs further investigation. And it is a question that deserves an honest answer.
NIPT is safe, reliable, and carries no risk to the pregnancy. However, it does not provide a definitive diagnosis, as it is a screening test—even if it is highly accurate. Because a positive result means increased probability, not certainty, definitive confirmation can only be obtained through amniocentesis.
Amniocentesis provides a definitive diagnosis through a full karyotype. However, it is an invasive procedure with a small but real risk of miscarriage (~0.1–0.5%).
In practice, NIPT often serves as an intermediate step: if the result is negative, many couples avoid amniocentesis altogether. If it is positive, amniocentesis provides definitive confirmation before any decisions are made.
There is no single right choice for everyone. There is the right choice for you, and that is discussed on an individualized basis.
Which NIPT should I choose?
There are several tests available on the market. The question “which is the best?” does not have a single answer, because it depends on exactly what you need: are you screening only for the three most common trisomies, or do you also want screening for microdeletions? Are you carrying twins? How many weeks pregnant are you? How quickly do you need the result?
These parameters determine the choice, and this is something we evaluate together based on your individual profile.
When are the results available?
Usually within 7–14 business days from the blood draw. Samples are sent to specialized laboratories, in most cases abroad, for analysis.
In rare cases, the laboratory may request a new sample when the concentration of fetal DNA is not sufficient. This is not related to the health of the pregnancy.
Frequently Asked Questions (FAQ)
No, it is a high-accuracy screening test. A positive result needs to be confirmed with amniocentesis before any decisions are made. A negative result significantly reduces the risk, without eliminating it entirely.
Yes, but the analysis is more complex, and not all tests support twin pregnancies equally well. In these cases, the choice of test is made with particular care.
No, none at all. It is a simple blood draw that can be done at any time of day, with no preparation required.
In Greece, it is not covered by EOPYY. Some private insurance plans may offer partial coverage.
The first step is to talk to your doctor, not to jump to conclusions on your own. A positive NIPT result is not a definitive diagnosis, and the next steps are always evaluated calmly and on an individual basis.
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