Understand Non-invasive Prenatal Test (NIPT) and Understand NIPT Results

Advancements in genetic testing have enabled the most accurate and sensitive detection of fetal chromosomal abnormalities via the analysis of cell free DNA (cfDNA) derived from fetal placenta in the maternal blood. The American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal Fetal Medicine (SMFM) jointly and specifically stated in the new clinical management guidelines (ACOG Practice Bulletin #226, 2020) that NIPT is the most sensitive and specific screening test for common fetal aneuploidies, and that all pregnant women, regardless of age or other risk factors, should be offered prenatal screening for fetal chromosomal abnormalities.  

As An Expecting Mother, There Are Three  Options To Consider Regarding Prenatal Screening:

1)  To have no prenatal genetic testing or testing before your baby is born.
2)  To have prenatal genetic testing during your pregnancy.  If the screening test results come back as high risk for a genetic condition, to consider diagnostic testing such as chorionic villus sampling, also known as CVS or amniocentesis.
3)  To bypass prenatal genetic testing and have diagnostic testing which would be CVS or amniocentesis.

Non-Invasive Prenatal Testing or Cell Free DNA Screening: – A Screening Option:

Non-Invasive Prenatal Screening Testing (NIPT) is an optional blood test that can be performed any time after 10 weeks of pregnancy.

NIPT can tell you the chance or risk your developing baby has for:

Down syndrome or trisomy 21
Trisomy 18 and 13
Sex chromosome disorders
Genetic conditions related to copy number changes such as 22q microdeletion syndrome
NIPT can also predict the gender of your baby in most cases, if you choose to know

How Does NIPT Work?

Our blood contains fragments of DNA known as cell free DNA.
When a woman is pregnant, her blood will also contain DNA fragments or pieces from the placenta which has a genetic makeup that is usually identical to that of her developing baby.
By analyzing these DNA fragments in Mom’s blood, it can be determined if the baby has an increased or decreased chance for certain genetic conditions.

What Can NIPT Tell Me About My Pregnancy?

NIPT is a screening test that can tell you if your pregnancy is at a higher or lower risk for certain genetic conditions.

Because NIPT is a screening test and not a diagnostic test, it gives the results of whether your baby have an increased risk of having a chromosomal aneuploidy.

If your NIPT test results come back as low risk, the chance that your baby has the condition is lower, but not zero.

If NIPT results come back as high or increased risk, this may create worry and uncertainty about what to do next.

If your NIPT results come back as high risk, then you will need to consider follow up diagnostic testing such as chorionic villus sampling (CVS) or amniocentesis.

Your doctor may refer you to a Genetic Counselor who will discuss your test results with you.

What Is Diagnostic Testing?

Diagnostic testing such as chorionic villus sampling (CVS) or amniocentesis can tell for certain whether or not a genetic condition is present in your baby by direct testing of your developing baby’s DNA.

CVS and amniocentesis are invasive procedures where your doctor will insert a very fine needle into your abdomen to collect cells for DNA analysis.

So How Do You Decide Whether To Have NIPT Or Any Prenatal Genetic Testing?

The decision to undergo any prenatal genetic test is a personal choice and may be very different from that of your friend or relative, and that’s ok.
In most cases, the best way to make a decision about whether NIPT is right for you is to be informed about the test advantages and limitations.

NIPT Testing Options

EnVISION® Prenatal Screening

EnVISION® Prenatal Screening is a major advance in prenatal testing based on genome deep sequencing. It is a non-invasive screening test (NIPT) that enables assessment of over or under representation of chromosomes from maternal whole blood samples. The test is developed by Otogenetics using Illumina VeriSeq NIPT Solution with the VeriSeq Assay Software. The validated NIPT screening test provides the information for chromosomes 21, 18, 13, X and Y with increased risks for trisomy 21, 18, 13 and sex chromosome aneuploidies reported. Gender information is available for reporting. The test reports for both singleton and twin pregnancies. 22q11.2 microdeletions can be selected for analysis and reporting for singleton pregnancies. 

EnVISION® Prenatal Screening has the lowest redraw rate and not-resulted rate. The redraw rate is 0.64%, the lowest in the industry. In addition, 87.5% of the redraws are resulted. The overall not-resulted rate is 0.08%, the lowest in the industry. 

 

ClariTest Core Prenatal Screening

ClariTest Core Prenatal Screening (NIPS) is a microarray-based non-invasive screening test using the Ariosa core technology.  The test reports trisomy 21, Trisomy 18, Trisomy 13, sex chromosome aneuploidies, and 22q11.2 microdeletions.