When is the Best Time for Non-Invasive Prenatal Screening (NIPS)?

At JunoDx™, we’re making it easier to access high-quality reproductive genetic testing. We believe everyone deserves access to prenatal genetic care, so we’re leveraging our clinical expertise and science-backed research to answer your most pressing questions about genetic screening during pregnancy.

What is non-invasive prenatal screening (NIPS)?

Non-invasive prenatal screening is a laboratory test that can help you learn your baby’s chance of being born with certain genetic conditions. You may also hear NIPS be called non-invasive prenatal testing (NIPT), but NIPS and NIPT are the same thing. 

This test looks through your blood for tiny fragments of DNA called cell-free DNA (or circulating cell-free fetal DNA). While most DNA fragments in your blood are from your cells, a portion of the fragments is from the placenta and from your baby. Non-invasive prenatal screening analyzes these fragments for specific chromosomal anomalies, like trisomies.

If you’re interested in non-invasive prenatal screening, consider whether you want to have your sample collected in a doctor’s office or in the comfort of your own home. At-home tests may take less time and cost less money than in-office blood draws while still providing fast and reliable results.

Depending on your preference, you’ll have your blood drawn by a healthcare professional (such as in a lab or at the doctor’s office) or use a finger-prick testing kit at home. Either way, your blood sample will go to a lab to be analyzed. NIPS typically screens for Down syndrome (trisomy 21), Patau syndrome (trisomy 13), and Edwards syndrome (trisomy 18). It can also look for differences in the number of sex chromosomes — that is, extra or missing copies of the X chromosome or Y chromosome.

NIPS is more accurate than traditional first-trimester screening, also called maternal serum screening. Still, NIPS is not a diagnostic test. Your NIPS result can’t tell you for sure whether your baby has a specific genetic condition. Instead, your NIPS result provides the probability of specific chromosome variations in your pregnancy. You can use this information to help you decide how to proceed with follow-up care, such as ultrasounds, appointments with one or more specialists, counseling, or additional testing.

When’s the best timing for NIPS?

Non-invasive prenatal screening can be done as early as the ninth week after your last menstrual period. There’s no official “deadline” for NIPS, either, so it’s technically available all the way through your pregnancy. You’ll get the most benefit from the information NIPS provides earlier in your pregnancy, though. The sooner you know your pregnancy’s chance for certain conditions, the sooner you can use that information to make informed decisions about your prenatal care, delivery, and beyond.

What happens after NIPS?

After you receive your NIPS result, your healthcare provider can help you understand the different options moving forward based on the result and any other important information from your medical care. For example, while it’s always recommended to meet with a genetic counselor following a screen-positive (high-risk) NIPS result, some people with screen-negative (low-risk) NIPS results may still want to discuss their family history or other health concerns with a genetic counselor – not all health conditions can be addressed by NIPS! Genetic counselors are specially trained to provide comprehensive information and help you decide whether to have invasive diagnostic testing, like amniocentesis or chorionic villus sampling (CVS). The decision to pursue CVS or amniocentesis is an especially important consideration for those with a screen-positive (high-risk) NIPS result.

Your healthcare provider can also help you understand which prenatal ultrasounds are available and important for your prenatal care, depending on the timing of your NIPS.

Non-invasive prenatal screening can be done as early as the tenth week after your last menstrual period and all the way through your pregnancy.


What happens if you do NIPS too early?

NIPS is offered at 9 weeks gestation and beyond because that’s when most people’s blood has enough DNA from the fetus and the placenta to generate accurate results. If you have your blood collected for NIPS too early, your sample may not have enough of your baby’s genetic information to make any conclusions about their chance for chromosomal conditions. This type of uninformative situation is referred to as having called a low fetal fraction on NIPS because the fraction or proportion of the baby’s DNA in the blood is insufficient to provide quality NIPS results.

NIPS gives expecting parents screening-level answers to some pretty big questions about their baby’s health, and it’s available earlier than many other prenatal laboratory tests and ultrasounds. Learning about fetal health conditions early in your pregnancy gives you as much time as possible to research and prepare for any special care your baby may need before and after their birth.

NIPS results can tell you the sex of your baby, but that’s not their main purpose. If you’re interested in finding out your baby’s gender without additional genetic screening, check out our at-home Juno Birch™ Fetal Gender Test.



 JunoDx.com and the materials and information it contains are not intended to be and do not constitute medical advice, other health advice, or diagnosis.  Do not use JunoDx.com or the materials and information published at JunoDx.com as a substitute for medical care and treatment. You should always consult with a qualified physician or healthcare provider about your specific circumstances. 

September 30, 2022 — Stephanie McClintock