Addressing myths on prenatal genetic testing

Prenatal genetic testing is now quite affordable and being increasingly used for improving reproductive outcomes in every pregnant woman as genetic testing prenatally, a.k.a before birth has given the opportunity to screen for a variety of severe genetic abnormalities and take necessary action in time. This helps in preventing the birth of children with genetic birth defects thus saving financial and emotional burden on the family.

With the advent of such testing, couples are now able to obtain information about genetic disorders of their foetus and make an informed decision about the same. In an interview with HT Lifestyle, Dr Veronica Arora, Assistant Consultant at Institute of Medical Genetics and Genomics at Sir Ganga Ram Hospital, revealed, “Genetic testing is not offered to obtain information about the foetus to predict non-disease-related traits. Such practice is strongly condemned. Some common myths about prenatal genetic testing include that it is only done for older women, it is very expensive, it is only done for Down syndrome, not required in the absence of family history, or done only for high-risk women.”

Highlighting that testing in the prenatal scenario includes non-invasive and invasive genetic tests, she elaborated -

• Non-invasive tests: Biochemical markers, non-invasive prenatal screening are those which are performed on the blood of the mother. Testing for common aneuploidies and thalassemia is included in this category, and these are offered universally to all pregnant women.
• Invasive genetic testing: Amniocentesis or Chorionic villus sampling is limited to fetuses at risk of having a genetic disorder. This includes those at risk due to positive family history, advanced maternal age, positive screening tests for aneuploidies or ultrasound abnormalities.

Addressing myths on prenatal genetic testing, Dr Ramesh Hariharan, CEO and Co-Founder of Strand Life Sciences, shared -

1. Prenatal genetic testing can help determine if the baby, while still in the mother's womb, has a genetic abnormality.
2. Pre-natal testing need not be invasive for the baby; some abnormalities in the baby can be detected from the mother's blood; these include large scale genomic abnormalities that cause Down's syndrome.
3. Not all abnormalities can be easily detected from the mother's blood though, particularly finer genetic abnormalities, those may need a procedure called amniocentesis or CVS to access cells from the baby.
4. All positive results detected from mother's blood should be confirmed by an amnio or CVS.