Prenatal testing key to early detection of genetic disorders

There are many kinds of tests done during or before pregnancy to assess the risk of genetic disorders
Last Updated 06 May 2022, 10:09 IST

Genetic disorders can cause serious health conditions and congenital disabilities in the baby.

With prenatal genetic testing, pregnant and expecting mothers and their healthcare teams may identify possible challenges early.

With chromosomal testing, doctors caring for expectant mothers can understand the problems with the unborn baby.

Studies suggest that chromosomal abnormalities occur in about 1 of 200 live births. Due to a large number of births (26 million per year), India has the largest number of babies born with chromosomal disorders in the world (1,30,000 per year).

Prenatal testing includes screening and diagnostic tests. Screening tests can provide information regarding the risk of having a baby with certain disorders. Diagnostic tests are definitive tests, and they can identify whether the baby has a congenital disability or not.

Types of tests done during or before pregnancy to find out about genetic conditions that may affect your baby:

Carrier screening

Carrier screening tests are a type of genetic test that can determine the status of any common recessive genetic diseases, including spinal muscular atrophy, cystic fibrosis, and Fragile X syndrome.

Chromosomal Microarray tests

Genetic conditions can cause miscarriage or stillbirth. When a baby dies in the womb before the 20th week of pregnancy, this is referred to as a miscarriage. Chromosome abnormalities cause more than half of all recurrent miscarriages. If a woman or couple wants to know the causes of recurrent miscarriages, chromosomal microarray tests can help her or them understand the reason behind it.

Screening tests

First-trimester screening tests can tell you if your baby is at risk for certain genetic conditions. Expectant mothers can get their prenatal tests during the first or second trimester of pregnancy. Tests such as dual marker tests, maternal serum screening, and non-invasive prenatal tests (NIPT) can determine the fetus's risk of being born with certain genetic abnormalities.

The NIPT early detection of chromosomal abnormality test is done after nine weeks of pregnancy. It looks for chromosomal disorders caused by the presence of an extra or missing copy of a chromosome. The results help get insight into genetic abnormalities from as early as the tenth week of pregnancy.

An early prenatal genetic screening can help healthcare providers calculate specific risks of Down's syndrome, Turner syndrome or other genetic disorders.

Diagnostic tests

Diagnostic tests include amniocentesis and chorionic villus sampling (CVS) test, which will reveal whether your baby is at risk for a condition. After the baby's birth, the healthcare team will also check your baby's blood to check for any genetic disorder.

Reputed molecular diagnostic companies offer these tests that provide accurate and credible results. After the testing, couples or expectant mothers can talk with their doctor and genetic counsellor to understand how the test results may affect them, their baby and the family.

Learning about any genetic disorder in their baby can be overwhelming for any mother or a couple. But these early warnings are valuable because they help provide insight into the development of complications during pregnancy.

(Neeraj Gupta, is the founder and CEO of Genes2Me, a leading company in the Molecular Diagnostics space in India. Genes2Me is a NABL accredited diagnostic lab.)

(Published 06 May 2022, 10:09 IST)

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