NIPT test: what non-invasive prenatal testing screens for and what a result means
In this article
The NIPT test (non-invasive prenatal testing) is a blood test from you that screens your baby for Down syndrome and two other chromosome conditions, trisomy 18 and trisomy 13. SingHealth says it analyses DNA from the placenta in your blood, which is usually the same as your baby's. KKH takes the sample from 10 weeks. It is a screening test, so a high-chance result needs a diagnostic test to confirm it.
| What it is | A blood sample from the mother |
|---|---|
| From | 10 weeks of pregnancy at KKH |
| Screens for | Down syndrome, trisomy 18 and trisomy 13 |
| Picks up | About 99% of Down syndrome cases, SingHealth says |
| Results | KKH's lab lists a 14 day turnaround |
| If high chance | A diagnostic test such as CVS or amniocentesis |
What NIPT looks for
The placenta sheds tiny fragments of DNA into your bloodstream, and NIPT reads them. ACOG calls this cell-free DNA. SingHealth says NIPT gives a risk estimate for Down syndrome, trisomy 18 and trisomy 13, and that about 99% of Down syndrome cases can be detected this way.
At KKH the test used is the Harmony Prenatal Test. KKH's laboratory says it can also identify the baby's sex if you ask, and screen for differences in the sex chromosomes and a small missing piece of chromosome 22 called 22q11.2 microdeletion.
NIPT or the first trimester screen
The first trimester screen (FTS) pairs a blood test with an ultrasound between 11 weeks and 13 weeks 6 days that measures the fluid behind your baby's neck. SingHealth says NIPT seems to pick up more Down syndrome than the FTS.
But NIPT is only a blood test, so it cannot see structural problems such as heart defects, which SingHealth says are seven times more common than Down syndrome. For that reason KKH still recommends the FTS and calls it its gold standard for Down syndrome testing. You can have both, and SingHealth notes that some women get no NIPT result at all, which is another reason KKH suggests doing the FTS anyway. Our guide to prenatal check-ups and scans shows where both sit in the first trimester.
What a high-chance result means
A screening result is a probability. ACOG says any screening test can give a false positive, where it flags a problem that is not there, and that a positive cell-free DNA result should be followed by a diagnostic test.
The two diagnostic tests SingHealth describes are chorionic villus sampling (CVS), which takes a small sample from the placenta, usually at 10 to 14 weeks, and amniocentesis, which takes a little of the fluid around the baby, usually after 16 weeks. Both use a fine needle through your tummy, and SingHealth puts the miscarriage risk at KKH at 0.3%, or 1 in 300. Whether to go further is your choice, made with your obstetrician.
Who can have NIPT, and what to ask first
KKH's lab takes NIPT samples at 10 weeks of gestational age or later, for single and twin pregnancies only. Like the other Down syndrome screens, it is your choice.
Age alone is not a reason to skip it. SingHealth says most babies with Down syndrome are born to younger women, simply because younger women have more babies, and that every pregnancy carries some risk. Before the blood draw, ask your clinic for the current price, whether it can be claimed, and how you will be told the result. Bring those questions to your antenatal visit at around 10 to 12 weeks.
Frequently asked questions
What does non-invasive prenatal testing mean?
Non-invasive prenatal testing: a blood test from the mother that screens the baby's chance of Down syndrome, trisomy 18 and trisomy 13. It needs no needle near the baby, which is what non-invasive means.
Is the Harmony test the same as NIPT?
Harmony is one brand of NIPT. KKH's laboratory runs the Harmony Prenatal Test as its NIPT screen for trisomy 13, 18 and 21.
Can NIPT tell me the baby's gender?
Yes, if you want to know: KKH's laboratory says the test includes an option to identify the baby's sex, so tell your doctor before the blood draw.
How accurate is NIPT?
Very good for Down syndrome, at about 99% detection according to SingHealth, but not perfect. ACOG says false positives and false negatives happen, so a high-chance result needs a diagnostic test before any decision.
Related terms
- Antenatal (also Prenatal): Antenatal means before birth. Antenatal care is the check-ups, scans and tests you get while you are pregnant.
- Trimester: One of the three stages of pregnancy, each about three months long.
- Gestational Age: How far along your pregnancy is, in weeks and days, counted from the first day of your last period.
- EDD (Estimated Due Date): The date your baby is expected: 40 weeks from the first day of your last period, checked by a dating scan.
- SingHealth (KKH) - Introduction to Down syndrome testing (read 9 November 2026)
- KKH - eLab Book: non-invasive prenatal testing (NIPT) (read 9 November 2026)
- KKH - Laboratory disciplines: NIPT (read 9 November 2026)
- SingHealth - First trimester screening for Down syndrome (read 9 November 2026)
- ACOG - Prenatal genetic screening tests (read 9 November 2026)
