NIPT Test in Delhi — Non-Invasive Prenatal Testing for Down Syndrome, Trisomy & Chromosomal Conditions

NIPT — Non-Invasive Prenatal Testing — is the most accurate prenatal screening test currently available for chromosomal conditions. By analysing fragments of fetal DNA circulating in the mother's bloodstream from as early as 10 weeks of pregnancy, NIPT detects Down syndrome (Trisomy 21), Edwards syndrome (Trisomy 18), Patau syndrome (Trisomy 13), sex chromosome abnormalities, and — on extended panels — microdeletion syndromes, all from a single blood draw with no risk to the fetus.

At the Fetal & Genetic Clinic in Chittaranjan Park, New Delhi, NIPT is offered not as a standalone blood test but as a specialist consultation — with Dr. Ashutosh Gupta, DM Medical Genetics (SGPGIMS), providing pre-test counselling, result interpretation, and a clear clinical pathway for every outcome. This page explains everything you need to know about NIPT: how it works, who should have it, what it detects, what different result types mean, and what to do after a positive result.

What Is NIPT — How Non-Invasive Prenatal Testing Works

During pregnancy, small fragments of placental DNA — known as cell-free fetal DNA, or cfDNA — are shed into the mother's bloodstream. By 10 weeks of gestation, fetal cfDNA typically makes up 4 to 20 percent of the total cell-free DNA in maternal blood, with the fraction rising as pregnancy progresses. NIPT isolates and analyses these fragments to count the proportional representation of each chromosome.

In a chromosomally normal pregnancy, chromosome 21 accounts for a predictable fraction of the total cfDNA. In a pregnancy affected by Trisomy 21, the fetus has three copies of chromosome 21 instead of two — meaning chromosome 21 fragments are slightly overrepresented in the maternal bloodstream. NIPT detects this fractional excess with remarkable sensitivity.

The test is performed on 10 ml of maternal blood, drawn from the mother's arm in the standard way. No needle approaches the baby, the placenta, or the amniotic cavity — hence the 'non-invasive' designation. The blood sample is sent to a specialist genomics laboratory where next-generation sequencing (NGS) is used to analyse millions of cfDNA fragments. The result is generated as a probability — typically expressed as 'high risk', 'low risk', or 'inconclusive' — for each chromosomal condition on the panel.

The fetal DNA fraction in the sample is critical to result validity. Samples with a fetal fraction below 4 percent — more likely in early pregnancy (under 10 weeks), in pregnancies with obesity (higher maternal DNA dilutes fetal fraction), or in some technical failures — may return an inconclusive result requiring a repeat draw.

NIPT is appropriate for any pregnant woman who wants the most accurate available screening for chromosomal conditions. While it was originally recommended only for high-risk pregnancies, the combination of high sensitivity, low false-positive rates, and no procedural risk makes it a reasonable choice across all risk categories. It is particularly indicated in:

• Advanced maternal age (35 or older): Chromosomal risk — particularly Trisomy 21 — increases with maternal age. NIPT provides highly accurate risk stratification with no procedural risk.
• High-risk combined first-trimester screen: If the NT scan combined with PAPP-A and free beta-hCG has returned an intermediate to high risk result (1:100 to 1:1,000), NIPT refines risk stratification and may avoid the need for invasive testing in a significant proportion of cases.
• Elevated nuchal translucency (NT): An NT above 2.5–3.0 mm warrants further assessment. NIPT is appropriate for intermediate NT elevations; very high NT (above 3.5 mm) warrants direct discussion about CVS or amniocentesis in addition to NIPT.
• Previous pregnancy or child affected by chromosomal condition: Couples with a history of a chromosomally abnormal pregnancy have a modestly elevated recurrence risk and typically prefer the reassurance of NIPT or diagnostic testing in subsequent pregnancies.
• Parental anxiety about chromosomal conditions: Even in low-risk pregnancies, NIPT provides a higher level of reassurance than standard combined screening. Many couples elect NIPT for peace of mind.
• Multiple marker anomalies on ultrasound: When multiple soft markers for chromosomal abnormality are present on the anomaly scan, NIPT offers a non-invasive intermediate step before proceeding to amniocentesis.
• IVF pregnancies: Pregnancies conceived by IVF — particularly using donor eggs or with a history of implantation failure — may have slightly elevated chromosomal risk and are commonly managed with NIPT.

NIPT is not appropriate — or is of limited value — in the following situations: where a definitive chromosomal diagnosis is already required (proceed directly to CVS or amniocentesis); where a structural anomaly has been identified on scan that needs chromosomal confirmation beyond the scope of NIPT; or where gestational age is below 10 weeks (insufficient fetal DNA fraction). Dr. Gupta will advise on the most appropriate testing pathway for your specific situation during consultation.

What Does NIPT Test For? — Conditions Detected with Detection Rates

The range of conditions NIPT can detect depends on which panel is ordered. The table below summarises the chromosomal conditions screened by NIPT, their detection rates in current laboratory practice, and their key clinical features. Detection rates quoted are from peer-reviewed published literature using current next-generation sequencing platforms.

Important note: Detection rates vary between laboratories and between specific NIPT platforms. The figures above represent averages from published validation studies. A detection rate of ≥99% for Trisomy 21 means that NIPT will correctly identify a Down syndrome pregnancy in 99 or more of every 100 affected cases. The false positive rate — the rate of high-risk results in unaffected pregnancies — is less than 0.1% for the common trisomies, meaning fewer than 1 in 1,000 unaffected pregnancies will receive a false high-risk result.

Basic NIPT vs Extended NIPT Panel — What Is the Difference?

When you are offered NIPT, you may be asked to choose between a basic panel and an extended panel. Understanding the difference helps you make an informed decision about what is right for your pregnancy.

Basic NIPT Panel

The basic NIPT panel screens for the three most clinically significant autosomal trisomies: Trisomy 21 (Down syndrome), Trisomy 18 (Edwards syndrome), and Trisomy 13 (Patau syndrome). Most basic panels also include sex chromosome abnormalities — Turner syndrome (45,X), Klinefelter syndrome (47,XXY), Triple X (47,XXX), and Jacob's syndrome (47,XYY). The basic panel detects the chromosomal conditions responsible for approximately 90 percent of all clinically significant aneuploidy identified prenatally.

The basic panel is appropriate for most pregnancies — it addresses the chromosomal conditions for which there is the best-established clinical evidence, the highest detection rates, and the clearest downstream management guidance.

Extended NIPT Panel — Microdeletions & More

Extended NIPT panels add screening for chromosomal microdeletion syndromes — conditions caused by small deletions of chromosomal material that cannot be detected by standard karyotype analysis but can cause significant clinical problems. The most clinically important microdeletion syndrome detectable by NIPT is 22q11.2 deletion (DiGeorge syndrome), which is associated with congenital heart disease, immune deficiency, cleft palate, and learning difficulties, and occurs in approximately 1 in 4,000 pregnancies.

Other microdeletions included on extended panels vary by laboratory — commonly including 1p36 deletion, Cri-du-chat syndrome (5p deletion), Prader-Willi and Angelman syndromes (chromosome 15), and Wolf-Hirschhorn syndrome (4p deletion). Extended panels may also screen for additional trisomies beyond 13, 18, and 21.

The detection rates for microdeletion syndromes are somewhat lower than for the common trisomies (typically 70–85%), and the positive predictive value is more variable — meaning extended panels carry a higher rate of results that require follow-up testing before a clinical decision can be made. Whether an extended panel is appropriate depends on clinical risk factors and the patient's preferences. Dr. Gupta advises on panel selection during pre-test consultation.

How NIPT Compares to the NT Scan and Amniocentesis

One of the most common sources of confusion in first-trimester pregnancy care is understanding how NIPT, the NT scan (Combined First-Trimester Screen), and invasive testing (CVS or amniocentesis) relate to one another. These are not interchangeable alternatives — each serves a distinct clinical purpose. The table below clarifies the key differences:

The critical principle: NIPT is a screening test, not a diagnostic test. A high-risk NIPT result means there is a significantly elevated probability of a chromosomal abnormality — it does not mean the baby definitely has that condition. A positive NIPT result must always be confirmed by CVS or amniocentesis before any irreversible clinical decision is made.

Many pregnancies are managed with both the NT scan (for anatomical assessment and pre-eclampsia screening) and NIPT (for high-accuracy chromosomal screening) — with the combination providing the most complete first-trimester evaluation available.

Understanding Your NIPT Result — Low Risk, High Risk & Inconclusive

Low Risk (Screen Negative)

A low-risk NIPT result means the fetal cfDNA profile shows no significant excess of chromosomal material for the conditions screened. For the common trisomies, a low-risk result reduces the residual risk to approximately 1 in 10,000 or less — providing substantial reassurance. However, a low-risk NIPT result does not guarantee a chromosomally normal pregnancy. NIPT does not detect all chromosomal abnormalities, does not assess fetal structure, and cannot detect single-gene disorders (such as cystic fibrosis or spinal muscular atrophy) unless those are specifically included on a targeted panel. A low-risk NIPT result should still be followed by the standard 19-week Level II anomaly scan.

High Risk (Screen Positive)

A high-risk NIPT result indicates that the fetal cfDNA analysis has found a significant excess of material from the chromosome in question, and that the probability of the corresponding chromosomal condition is elevated. The positive predictive value (PPV) of a high-risk NIPT result — the probability that the result reflects a true chromosomal abnormality — varies depending on which condition is being considered and the patient's background risk. For Trisomy 21 in a 35-year-old woman, the PPV of a high-risk NIPT result may be as high as 90 percent or more. For rarer conditions like microdeletions, the PPV may be significantly lower. A high-risk NIPT result is not a diagnosis. It requires confirmation by CVS (if gestation permits) or amniocentesis before any clinical decision is made.

Inconclusive or No-Result

Approximately 1 to 3 percent of NIPT samples return an inconclusive result — most commonly due to a low fetal DNA fraction in the maternal sample. This may occur in early pregnancy (below 10 weeks), in pregnancies with high maternal BMI (where maternal DNA dilutes the fetal fraction), or occasionally due to laboratory technical issues. An inconclusive result does not indicate a chromosomal problem. It requires a repeat blood draw after two weeks to allow the fetal DNA fraction to rise.

What Happens After a Positive NIPT Result?

Receiving a high-risk NIPT result is an acutely stressful experience for any expectant family — particularly given that NIPT is often ordered with the expectation of reassurance. The most important message is this: a high-risk NIPT result is not a diagnosis. It is the beginning of a clinical pathway, not the end of one.

The immediate next steps after a high-risk NIPT result are:

• Specialist genetic counselling: A consultation with a fetal medicine specialist or medical geneticist — not a lab technician or a general obstetrician — to understand exactly what the result means, what the positive predictive value is for your specific combination of conditions and risk factors, and what the full range of options is. Dr. Gupta's DM in Medical Genetics from SGPGIMS positions him as exactly the right specialist for this conversation.
• Confirmatory diagnostic testing: CVS at 12 to 13 weeks or amniocentesis at 16 weeks to obtain a definitive chromosomal diagnosis. The decision between CVS and amniocentesis depends on gestational age and urgency. Dr. Gupta performs both procedures at the Fetal & Genetic Clinic with over 3,000 invasive procedures to his name.
• Detailed structural assessment: A Level II anomaly scan and fetal echocardiography should be arranged, as many chromosomal conditions (particularly Trisomy 21 and Trisomy 18) are associated with structural abnormalities that have their own management implications.
• Multidisciplinary planning: If a chromosomal condition is confirmed on diagnostic testing, Dr. Gupta can facilitate referral to the appropriate specialist team — neonatology, paediatric cardiology, paediatric surgery — for pre-birth planning and counselling on what to expect after delivery.

A positive NIPT result in isolation should never lead to a clinical decision about the pregnancy. Confirmation first — always.

NIPT in Twin Pregnancies — What You Need to Know

NIPT is available in twin pregnancies but requires careful interpretation. In a twin pregnancy, the cfDNA pool in the maternal circulation comes from both placentas (dizygotic twins) or from a single placenta (monochorionic twins), meaning the fetal DNA fraction and the chromosomal signal are more complex to interpret than in singleton pregnancies.

In dizygotic (non-identical) twin pregnancies, each fetus contributes its own cfDNA to the maternal circulation. NIPT can detect a chromosomal abnormality in either fetus but cannot always determine which twin is affected. The overall detection rates for Trisomy 21 in dizygotic twins are slightly lower than in singletons (approximately 90–95% vs ≥99%). A high-risk NIPT result in a twin pregnancy requires particularly careful genetic counselling before any decision about confirmatory testing or management.

In monochorionic (identical) twin pregnancies, both fetuses typically share the same chromosomal constitution and the same cfDNA contribution — meaning a single high-risk result applies to both. Monochorionic twin pregnancies also carry the additional risks of twin-to-twin transfusion syndrome (TTTS) and selective fetal growth restriction, which require separate monitoring independent of NIPT results.

NIPT is not recommended as the sole screening modality in higher-order multiple pregnancies (triplets and above) due to the complexity of DNA fraction interpretation.

Why Choose Dr. Ashutosh Gupta for NIPT Counselling in Delhi?

NIPT is available at dozens of diagnostic labs in Delhi — as a blood draw, a form, and a result sent by email. What is significantly harder to find is expert clinical interpretation of that result, and a clear, supported pathway for whatever the result shows. That is what distinguishes a consultation at the Fetal & Genetic Clinic.

• Pre-test counselling as standard: Before NIPT is ordered, Dr. Gupta provides a structured counselling session covering the purpose of the test, what each panel screens for, the detection rates and false positive rates for your specific clinical scenario, what you will do with a high-risk result, and whether NIPT or direct invasive testing is more appropriate for your situation. This is not a formality — it is the most important part of the NIPT process.
• DM in Medical Genetics from SGPGIMS: No diagnostic lab in Delhi can offer NIPT result interpretation by a clinician holding this qualification. Dr. Gupta's genetic expertise means he understands NIPT results at a molecular level — including the significance of rare findings, mosaic results, inconclusive reports, and the difference in positive predictive value between different conditions.
• Post-test result interpretation in person: When your NIPT result arrives, you discuss it directly with Dr. Gupta — not through an automated email or a call centre. He explains what the result means for your pregnancy, addresses your questions, and advises on the appropriate next step for your specific clinical scenario.
• On-site CVS and amniocentesis if needed: If your NIPT result is high-risk and confirmatory testing is recommended, Dr. Gupta performs CVS at 12 weeks and amniocentesis from 16 weeks at the same clinic. There is no referral, no waiting list, and no handover to a different clinician.
• Integrated fetal medicine assessment: NIPT answers the chromosomal question — it does not replace the anatomy scan. Dr. Gupta's fetal medicine expertise means the complete first-trimester assessment — NT scan, combined serum screening, NIPT, and pre-eclampsia Doppler — can be co-ordinated and interpreted in a single clinical framework.
• South Delhi clinic — easy to reach: Fetal & Genetic Clinic, E-874, Basement, Chittaranjan Park, New Delhi — accessible from Greater Kailash, Kalkaji, Saket, Lajpat Nagar, Nehru Place, Noida, and Gurugram.

Book Your NIPT Test Consultation in Delhi

If you are considering NIPT, have already received a result that needs interpretation, or are unsure whether NIPT or another screening option is right for your pregnancy, a specialist consultation with Dr. Ashutosh Gupta provides the clinical guidance you need.