Aneuploidy Screening / NT / NB Scan

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Aneuploidy Screening / NT / NB Scan

A healthy human has 46 chromosomes, arranged in 23 pairs this genetic blueprint governs everything from our physical appearance to our behavior. Aneuploidy refers to conditions where there is an extra chromosome (trisomy) or a missing chromosome (monosomy). These chromosomal imbalances can significantly impact a pregnancy and the future health of the baby.

Unfortunately, aneuploidy is not uncommon. It occurs in 1 out of every 150 pregnancies and is a leading cause of early pregnancy loss. One of the most well-known examples of aneuploidy is Down Syndrome, also called Trisomy 21, which results from an extra chromosome in the 21st pair.

If you’re planning or already experiencing a pregnancy, you can consult expert fertility doctors in Amritsar for early detection and guidance.

What Are the Risks of Aneuploidy?

  • Increased chance of miscarriage or failure to carry to full term
  • Congenital defects in the baby
  • Lower cognitive function and intellectual delays
  • A range of functional or developmental abnormalities

What Causes Aneuploidy?

Aneuploidy can result from genetic factors, but it often happens randomly by chance, especially during cell division in early pregnancy. While the risk increases with maternal age, especially after 35, aneuploidy screening is recommended for all pregnancies, regardless of age.

When and How is Aneuploidy Screening Done?

Aneuploidy screening is non-invasive and typically includes:
  • NT (Nuchal Translucency) Scan:
    Done between 11 weeks + 5 days to 13 weeks + 5 days, this ultrasound measures fluid at the back of the baby’s neck, a key marker for chromosomal abnormalities.
  • Blood Test (Cell-free DNA Testing):
    A maternal blood sample is analyzed to detect fetal DNA fragments, helping to identify any extra or missing chromosomes.
These tests are offered at top gynecology and fetal medicine centers in Amritsar.

Accuracy of Screening Tests

  • First Trimester Screening: Detects trisomies with up to 87% accuracy.
  • Second Trimester Screening (15–20 weeks): Offers up to 81% detection rate for chromosomal conditions.
In cases where screening indicates a possible issue, your doctor may recommend additional diagnostic tests for confirmation, such as amniocentesis or chorionic villus sampling (CVS).
FAQ

Frequently Asked Question

No, it’s optional, but highly recommended, especially if there are risk factors or if it can offer peace of mind.
Not necessarily. It only indicates an increased risk. A diagnostic test is needed for confirmation.
Yes, both the NT scan and the blood test are completely safe and non-invasive.
Yes. While age increases risk, aneuploidy can occur in any pregnancy, so screening is advisable for all expectant mothers.