
Generation NIPT is a highly accurate, non-invasive prenatal screening test, based on whole genome sequencing (WGS) with proprietary algorithms. The test analyses circulating cell-free fetal DNA, detected from a maternal blood sample, with testing from as early as 10 weeks gestation.
The clinical utility and benefit of the Generation test has been demonstrated in all pregnant women – regardless of age or risk category – in multiple published studies of thousands of pregnant women, for both singleton and twin pregnancies. Clinical best practice guidelines from Australian and international medical societies recommend that all pregnant women, regardless of risk status, should be offered the opportunity for discussion and choice regarding NIPT.
The Generation Plus test option should be considered only when there are specific indications of an increased risk of one of these microdeletion syndromes. Typical clinical indications include, but are not limited to:
The Generation Plus test is performed in an accredited laboratory in California and has a longer turnaround time (11 – 15 business days) than other Generation options.
This test is not recommended in an unselected/low risk cohort, where the Generation or Generation 46 screen should be considered instead. It is recommended that testing for microdeletion syndromes is accompanied by specialised genetic counselling.
Talk to your doctor about your options, and request an NIPT test.
Visit one of our collection centres to get your sample collected.
Your doctor will discuss any relevant findings and advise genetic counselling if necessary.
NIPT for fetal chromosomal aneuploidies has the highest detection rate and lowest false positive rate of available prenatal screening methods. Combined with the lowest reported failure rate, Generation NIPT ensures that more patients will avoid invasive diagnostic procedures.
NIPT is a highly accurate screening test. This means that if there is a true chromosomal aneuploidy in the fetus, it is highly likely that it will be detected by NIPT. However, a more clinically useful statistic is the positive predictive value (PPV) which is the chance that a high-risk correctly identifies true aneuploidy in the fetus. PPV is different for every woman, and is determined by factors including maternal age, type of aneuploidy, and personal and family medical history. For example, the chance of Down syndrome following a high risk test result is 94% for a 40-year-old woman and 63% for a 30-year-old woman. This variability in PPV, due to biological and technical false positive results, means that diagnostic testing by amniocentesis or chorionic villus sampling is strongly recommended prior to making definitive decisions regarding further pregnancy management.
Genomic Diagnostics provides a free genetic counselling service to explain the individual risks to every woman who has a high-risk result.
The Generation test was chosen for development by Genomic Diagnostics based on a careful evaluation of its quality and proven scientific performance.
The performance of next generation sequencing-based NIPT has been evaluated and published in numerous major studies, including clinical experience in over 34,000 patients from over 60 leading US medical research and teaching institutions.
Those findings have been replicated in other studies which includes the New England Journal of Medicine, one of the most prestigious international medical journals. These studies have found that the test performed substantially better than conventional tests under regular clinical conditions, with 1 in 4,000 false negative results, 1 in 500 false positive results, and the lowest test failure rate of any non-invasive prenatal test.
Generation uses the most advanced Whole Genome Sequencing technology and research has shown this is the most sensitive method available for NIPT.
Fetal fraction (FF) represents the percentage of cell free fetal DNA in the mother’s circulation. Measurement ensures the placental DNA can be detected in the maternal plasma in sufficient quantities to generate a meaningful result. A number of factors can influence the level including fetal aneuploidy. Generation testing uses a dynamic threshold, which looks at FF in combination with other sample-specific information, which reduced NIPT failures while ensuring accurate calls. Generation reliably provides accurate results on samples with a fetal fraction of <2%.
NIPT is the most accurate screening test for chromosomal abnormalities such as Down syndrome. Although serum biochemical screening with ultrasound is not as accurate as NIPT, patients can still be offered serum screening prior to NIPT, as it is a complementary test which detects a different range of abnormalities including neural tube defects and non-genetic abnormalities. NIPT, biochemical testing and ultrasound testing measure different things; the genetic code versus biochemical function and fetal anatomy respectively
Verifi™ and Verifi™ Plus are the manufacturer’s names for Generation and Generation Plus. Verifi™ is validated for aneuploidy of chromosomes 21, 13, and 18 in both singleton and twin pregnancies, with gestational age of at least 10 weeks 0 days. Aneuploidy of sex chromosomes are validated only for singleton pregnancies, while presence/absence of Y chromosome material is validated for twin pregnancies. Verifi™ Plus is validated for trisomies of all chromosomes, including 21, 13, 18, sex chromosome aneuploidies and for specific deletions in chromosomal regions 1p36, 4p16.3, 5p15.2, 15q11.2, 22q11.2, in singleton pregnancies, with gestational age of at least 10 weeks 0 days. Both Verifi™ and Verifi™ Plus are screening tests that look only for specific chromosomal abnormalities. A normal result does not eliminate the possibility that the pregnancy is associated with other full or partial chromosomal or abnormalities, birth defects, genetic conditions, or other conditions, such as open neural tube defects or autism. There is a small possibility that the test results might not reflect the chromosomes of the fetus but may reflect chromosomal changes of the placenta (confined placental mosaicism, CPM) or of the patient (chromosomal abnormalities in the patient). Examples include sex chromosome status (eg. XXX), or benign and malignant neoplasm in the patient. Some cases of CPM may be associated with a higher chance for pregnancy complications or for uniparental disomy (UPD), which may affect the growth and development of the fetus. Some of these rare chromosomal aneuploidies may only occur in mosaic form. Clinical consequences depend on the chromosome involved and cannot be predicted prenatally. This test, like many tests, have limitations, including false negative and false positive results. A negative test result does not eliminate the possibility of chromosomal abnormalities for the tested chromosomes or microdeletions. In the case of vanishing twin, the test result may reflect the DNA of the vanishing twin, leading to a higher probability of false positive, false negative results, or sex discordance. No irreversible clinical decision should be made based on these screening results alone. If definitive diagnosis is desired, chorionic villus sampling or amniocentesis would be necessary. In some cases, other testing may also be necessary.