Non Invasive Prenatal Testing (NIPT) or Non Invasive Prenatal Screening (NIPS) is a screening test for common chromosomal disorders with an accuracy or detection rate of greater than 99%. Generally the cell-free fetal DNA (cffDNA), which is the DNA of the unborn baby freely moving in the mother’s blood stream, begins to circulate in the mother’s system after 7-8 weeks of gestation. NIPT is done from the 10th week onwards to ensure enough cffDNA is available in the maternal blood stream.
Non Invasive Prenatal Testing also called NIPS ( Non Invasive Prenatal Screening) are advanced genetic tests conducted on normal blood samples that help identify women whose pregnancies have a high risk of carrying a fetus with a genetic abnormality. The principle of this technique is the peripheral blood collected contains cell-free fetal DNA (cffDNA), which is the DNA of the unborn baby freely moving in the mother’s blood stream. The test analyzes circulating cffDNA in the mother’s blood to screen for common genetic abnormalities with a reported accuracy & detection rate of more than 99%.
Screening is the first step & this identification helps determine the further course of action for doctors as well as the prospective parents. Statistically speaking there is a 3-4% chance of fetuses suffering from genetic conditions.
If a NIPT result comes back as high risk, the second step is to go for what are known as Confirmatory Tests. These tests confirm if the fetus is indeed affected by a genetic abnormality which is reflected in the primary screenings.
Confirmatory or Definitive tests for checking chromosomal abnormalities are invasive and carry a risk of miscarriage. NIPT helps identify those pregnancies that are at a high risk of having a chromosomal abnormality hence warrant an invasive test. Those pregnancies that are at low risk on NIPT need not expose their pregnancy to undue harm by doing an invasive test.
Established practice across the world in developed countries is for all couples who are planning on conceiving or those who have already conceived to be offered Prenatal Screenings by their doctors & NIPT is one type of Prenatal Screening. As screenings are predominantly woman focused, every woman planning or already pregnant should do this. It is recommended more so for women of advanced maternal ages as they have increased risk of having babies with genetic abnormalities.
Since genetic diseases can either be passed on from a parent to child or occur spontaneously during conception without any previous family history, ACOG, RCOG, RANZCOG & various other international medical & gynaecological societies recommend that these screenings be done for all women.
NIPT first and foremost gives expecting parents peace of mind by providing information of the health of their child much in advance. Secondly & more importantly, because genetic disorders are non-treatable, screenings give parents the choice & freedom to decide the outcome of their pregnancies & the future their loved ones.
But the most important aspect about NIPT is that it is a highly accurate screening test with a reported detection rate of more than 99.6%, more than any other Prenatal Screening, for Trisomy 13, 18 and 21 and it is non-invasive. Opting for an NIPT will enable you to decide for or against an invasive confirmatory test.
Yes, if you wish to know the health of your unborn child & not take any chances. As genetic disorders may not show up in routine checkups, it is impossible to know if the fetus is normal unless it is screened. Hence it is less of a need based requirement & more preemptive & preventive focused.
It is important to note that NOT all genetic & chromosomal disorders are inherited as some disorders occur spontaneously (de novo mutation) during conception; meaning no history of genetic disorders is even necessary for a child to suffer from one. Also, some inherited disorders do not show any signs or symptoms of their presence for generations together due to their recessive nature. This may erroneously be interpreted as ‘no family history of genetic disorders’. Which is why, across the globe in developed countries prenatal screenings are routine procedures.
If that is the case, one certainly needs to discuss this with their referring doctor. As prenatal screenings only give risk assessment for a given set of most commonly found genetic disorders in India, there are other less common ones which your doctor will need to request specifically for, in case there is a family history. These decisions are normally taken during the course of pregnancy when abnormalities are noted during routine checkups or when doctors are aware of a family history & want to rule out any chances of the fetus being abnormal. It is in the best interest of prospective parents to inform doctors about any family history of genetically inherited diseases to enable them to make informed decisions.
It can be done any time after 10 weeks of gestation for a singleton pregnancy and any time after 12 weeks in a twin pregnancy. NIPT cannot be done for multiple gestational pregnancies. Ideal time to do a NIPT is between 12 weeks to 16 weeks. Though NIPT can be done even later than 16 weeks, decision making on a high risk NIPT result becomes difficult as termination of an abnormal pregnancy is prohibited by Indian law after 20 weeks.
While the screening window for NIPT starts after 12 weeks, by Indian law, abortion is legal only up to 20 weeks, hence it is advisable to conduct a screening as early as possible.
It checks for following commonly found chromosomal abnormalities:
- Trisomy 9, Patau Syndrome (Trisomy 13), Trisomy 16, Edward Syndrome (Trisomy 18), Downs Syndrome ( Trisomy 21), Cat Eye Syndrome (Trisomy 22)
- Abnormality in sex chromosomes – Turner’s Syndrome , Jacobs Syndrome , Klinefelter Syndrome
- Few microdeletions
NIPT does not check for any structural abnormalities.
You should be screened for the most common & widespread disorders which the test already does. In addition, if there is any family history then you will require additional tests specific to those disorders which your consulting doctor will decide.
In most cases than not, your referring doctor will request these tests for you. But if you wish to do so directly or through your doctor who isn’t familiar with Lilac Insights, you can directly Contact Us & we will facilitate the process.
For NIPT the only requirement is pregnancy. You can get in touch with us or speak to your doctor for additional queries.
Normally one screening is all that is required. In this test there is less than a 1% chance of repeat screening which may be due to low proportion of fetal fraction as minimum of 4% fetal fraction is required to carry out the testing. Once a repeat sampling is done there is a 50% chance of the repeat sample still getting a fetal fraction lower than 4%. In such a situation a test failure report is issued. A repeat sampling or a test failure does not mean the fetus is abnormal. It just means that the sample is giving a lower yield of fetal DNA than can be analyzed. This can be due to many reasons, one of them being high BMI of the mother or obesity.
In other cases, especially for high risk results, doctors & patients might decide for an additional Combined Screening (a different screening from NIPT) before opting for an invasive Confirmatory Test.
For the fetus & the mother, there are no risks.
Regular blood drawn from the veins of the pregnant woman technically referred to as peripheral blood.
Any trained phlebotomist or a nursing staff can draw the sample for the screening.
Genetic testing & diagnoses differs from ordinary pathology in several ways, mainly that medical genetics is a separate vertical within the field of medical sciences. The qualifications, background, expertise & technologies required to conduct & understand these tests are different from ordinary pathology. Importantly, the resultant reports are also not simple computer outputs & require human intervention. Doctors & clinicians who do not have a genetic background are not medically equipped to address the complexities in the testing, diagnoses & interpretation of reports of genetic disorders.
No. Specialized labs like Lilac Insights which is a Genetic Health Assessment & Diagnostic Center will conduct prenatal screenings. Genetic screenings need well equipped technical labs and analytical support staff to perform the test and scientific experts to interpret the results. Also, they should be registered under the PCPNDT act.
In most cases if not all, the referring doctor.
Choosing the right genetic service provider is the first step to ensure your child’s future is in safe hands. You can click here to see Why Lilac Insights would be a good choice.
You may discuss this with your doctor & upon mutual agreement, provide us with the contact details. We will get in touch with the concerned person & facilitate the process. Being market leaders, there is a high chance that they are already working with us.
NIPT reports give you a risk assessment of the fetus being genetically abnormal. As per international protocols 1/250 is taken as a cut off; in other words 0.4%. If the pregnancy reflects anything higher than the cut off value, it is classified as high risk and anything below is low risk.
High risk implies the pregnancy is at a high risk of being affected with a genetic abnormality & the need for a secondary screening or a Confirmatory Test may be required. However, it does not completely exclude the possibility of the pregnancy being not affected with an abnormality & a residual chance of the fetus being completely normal still exists as the test is a ‘risk assessment’ & not a confirmation. This is known as False Positive. False Positives are a rare chance & the threat to the fetus is considered as near certain; as in the case of NIPT, it is has a 0.04% chance of diagnosing a normal fetus as genetically abnormal. Keeping the False Positive rate as low as possible is important as it prevents unnecessary miscarriages due to invasive procedures of Confirmatory Tests. If you are still unsure, you may Contact Us or your doctor.
Low risk implies the pregnancy is at a low risk of being affected with a genetic abnormality & there is no secondary or confirmatory testing required. However, it does not completely exclude the possibility of the pregnancy being affected with an abnormality & a residual chance of fetus being affected still exists as the test is a ‘risk assessment’ & not a confirmation. This is known as False Negative. False Negatives are a rare chance to the point of being not considered as a threat; as in the case of NIPT, it is has a 0.04% chance of diagnosing a genetically abnormal fetus as completely normal. If you are still unsure, you may Contact Us or your doctor.
Your doctor should be able to address all your questions. You may feel free to get in touch with our genetic counsellors if you wish.
Screening normally takes about 10 days post arrival of blood sample at the lab. Your doctor should have a digital report by the end of the second week.
All pricings will be provided by your referring doctor.
For getting a screening done, the simplest way is to speak to your consulting Obstetrician or Gynecologist. As Lilac Insights is a market leader, there is a good chance they are already availing of our services. In the event your doctor is not familiar with Lilac Insights, upon mutual discussion you may provide us with your doctor’s details & we will get in touch with them to facilitate the process.
You may also Contact Us directly & we will guide you through the process.