Skip to main content

    Fetal Conditions

    Chromosomal & Genetic Screening

    Screening and diagnostic tests to assess the risk of chromosomal conditions such as Down syndrome.

    What is Chromosomal & Genetic Screening?

    Chromosomal screening estimates the probability of a baby having a chromosomal condition such as Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), or Patau syndrome (trisomy 13). Screening methods include first-trimester combined screening (nuchal translucency scan + blood tests), non-invasive prenatal testing (NIPT) using maternal blood, and detailed ultrasound. Diagnostic tests such as amniocentesis or CVS provide definitive results.

    Why is it a Concern?

    Chromosomal conditions can affect a baby's physical and cognitive development. Some are compatible with life but require ongoing support; others carry a poor prognosis. The risk of chromosomal conditions increases with maternal age. Early information allows families to prepare, plan, and make informed decisions.

    Signs & Symptoms

    • Advanced maternal age (35 years or older)
    • Abnormal first-trimester screening results (elevated risk)
    • Increased nuchal translucency on ultrasound
    • Structural anomalies detected on ultrasound
    • Previous pregnancy affected by a chromosomal condition
    • Family history of genetic conditions

    How It is Monitored

    First-trimester combined screening is performed between 11 and 14 weeks. NIPT can be done from 10 weeks onwards. If screening results indicate elevated risk, diagnostic testing (amniocentesis or CVS) is offered to confirm or rule out a chromosomal condition. Genetic counselling is provided throughout the process.

    Why See an MFM Specialist?

    MFM specialists are trained in performing and interpreting nuchal translucency measurements, counselling about screening results, performing invasive diagnostic procedures (amniocentesis, CVS), and guiding families through complex decisions based on results.

    Dr. Kartik Balaraman Manages This Condition

    Dr. Kartik provides comprehensive chromosomal screening and counselling, including NIPT, nuchal translucency assessment, and diagnostic procedures. If you have questions about prenatal screening, speak with Dr. Kartik.

    Book Consultation

    Related reading

    Understanding the Detailed Anomaly Scan at 20 Weeks

    Frequently Asked Questions

    What is the difference between screening and diagnostic testing?

    Screening tests estimate the probability of a condition — they don't give a definitive answer. Diagnostic tests (amniocentesis, CVS) analyse the baby's chromosomes directly and give a definitive result, but carry a small procedural risk.

    What is NIPT?

    Non-invasive prenatal testing (NIPT) is a blood test that analyses fragments of the baby's DNA circulating in the mother's blood. It has a high detection rate for major chromosomal conditions with a very low false-positive rate.

    Is amniocentesis safe?

    Amniocentesis carries a small risk of miscarriage, approximately 0.1–0.3%. It is performed under ultrasound guidance and is generally well-tolerated.

    When can NIPT be done?

    Non-invasive prenatal testing can be performed from 10 weeks onwards. It's a blood test from the mother that screens for common chromosomal conditions like Down syndrome.

    Does screening affect whether I'll be offered diagnostic testing?

    Yes. Diagnostic procedures are offered when screening results are elevated risk or when an ultrasound finding suggests a chromosomal condition. Testing is your choice — Dr. Kartik will discuss implications in detail.

    Related Conditions

    Amniocentesis & CVS

    Diagnostic procedures to definitively test for chromosomal and genetic conditions in the baby.

    Detailed Anomaly Scans

    A comprehensive ultrasound examination at 18–22 weeks to check the baby's structural development in detail.

    Fetal Structural Anomalies

    When a detailed scan identifies a structural difference in the baby's development.

    Reviewed by Dr. Kartik Balaraman, Consultant OBGYN & Maternal Fetal Medicine Sub-Specialist ·

    This page is for general education and does not replace personalised medical advice. If you have concerns about your pregnancy or health, consult a qualified specialist directly.