How accurate is the Crysta NIPS for trisomies ?
The Crysta NIPS is > 99% accurate for the detection of trisomy 21, 18 and 13.
What is recommended for high risk patients ?
All high risks results should be reviewed by the healthcare provider and confirmed by further testing. This is usually an invasive procedure such as amniocentesis or CVS along with appropriate counselling.
Can the results report be given directly to pregnant women ?
We recommend that results are not given directly to the patient, but are explained with counselling and further advice by the healthcare professionals. They will explain the results to allow the pregnant woman to make informed choices about their pregnancy.
Can the Crysta NIPS be used for a contingent screening model ?
Yes. The Crysta NIPS is suitable as a first or second line screening test. Many of our healthcare providers offer the first trimester combined test and then offer the Crysta NIPS to the women who are high or intermediate risk. In addition, many providers offer the Crysta NIPS alongside an ultrasound as the first line screen.
Can the Crysta NIPS be used on patients expecting twins ?
The Crysta NIPS test is suitable for twin pregnancies. In the case of monochorionic twins the accuracy of the Crysta NIPS remains > 99% for trisomies. However, in dichorionic (non-identical) twins, the test sensitivity maybe reduced from > 99% to 95%. The test cannot tell which twin is high risk. If a high risk result is generated, selective invasive confirmatory testing would be required.
My patient has shown twin demise (vanishing twin) on ultrasound, can I use the Crysta NIPS ?
If there is evidence of the presence of a demised fetus (e.g. remnants seen by ultrasound), the Crysta NIPS is affected by DNA fragments being shed by the demised fetus until it is totally absorbed; in most cases this takes about 8 weeks. If the Crysta NIPS result is high- risk, it is impossible to tell if this is related to the live or demised fetus so as with all high-risk results this should be followed up with an invasive diagnostic test. If the result of the Crysta NIPS is low-risk, then routine antenatal care is appropriate and further counselling is not required.
What blood tube should be used for sending samples ?
Redcliffe recommends using a Streck Blood tube (cell-free DNA BCT Streck) as this keeps the blood stable for up to 14 days.
How long do the results take ?
Results should be available in 10-12 working days after sample receipt in the laboratory.
Can the Crysta NIPS be used on pregnant women who have cancer ?
Malignant tumours shed cell-free DNA fragments which can interfere with the Crysta NIPS and potentially giving an erroneous result. Therefore, if a pregnant mother has cancer, the Crysta NIPS should not be used.
Can the Crysta NIPS be used on pregnant women who have had a blood transfusion ?
There is a lot of debate around how long blood stays in the body which has come from a blood transfusion. As such, we take the cautious approach and recommend that the woman should not have had a blood transfusion within the last 12 months.
Can the Crysta NIPS be used in a pregnancy that follows a fetal loss and does the previous pregnancy result affect the test result ?
Previous pregnancies would not affect the test result. Cell-free DNA shed from the placenta disappears hours after the pregnancy is over.
Would the test work in a pregnant mother with a high BMI ?
Women with an elevated BMI would generally have a lower proportion of placental DNA to maternal DNA in her blood, this is called a "low fetal fraction". This is the result of increased blood volume resulting in a dilution of the cell free placental DNA in the mother's plasma. Some NIPS tests will not be sensitive enough to generate an accurate result on samples with decreased fetal fraction. Crysta NIPS however can produce an accurate result in samples that have as little as ≥ 3.5% fetal fraction.
Can Crysta NIPS be used in IVF with donor egg pregnancies ?
Yes, the Crysta NIPS can be used for IVF pregnancies where a donor egg is used.
Is the Crysta NIPS diagnostic ?
No, it is a screening test, not a diagnostic. As with all NIPS tests, our test analyses cell-free DNA from the placental-fetal unit, which is present in the mothers' blood stream. Various biological factors can mean that the result of an NIPS test is affected by issues in the placenta, such as confined placental mosaicism, or in the mother, such as copy number variant, mosaicism, or presence of a malignant tumour. Therefore, a high risk result may not accurately represent the fetus and must be checked with an invasive diagnostic test such as amniocentesis.
Which invasive diagnostic test is suitable for follow up testing ?
Although Chorionic Villus Sampling (CVS) can be conducted earlier in the pregnancy it tests a sample of the placenta, so if the result from the CVS was also high risk, it may be affected by confined placental mosaicism, and hence if positive for a trisomy the healthcare provider may wish to verify the result via an amniocentesis, particularly if no ultrasound abnormalities are present.
What microdeletions are screened for ?
Generally the professional bodies such as RCOG, ESHG, ASHG, FIGO do not recommend to routinely screen pregnant women for rare microdeletion syndromes with NIPS. However, in cases where the is a family history of microdeletion syndromes, the Crysta NIPS upon request can look at a panel of the six most common microdeletions which includes: DiGeorge syndrome, 1p36 deletion syndrome, Prader-Willi syndrome, Angelman syndrome, Cri-du-Chat syndrome and Wolf-Hirschhorn syndrome.
What do I need to get started ?
If you wish to send patient samples for analysis with the Crysta NIPS, please email @ email@example.com or call us @ +91-8882-914-915