Written By: Debjani Arora | Published : July 29, 2016 6:40 PM IST
There are various tests done during pregnancy to check if the foetus is suffering from any genetic or chromosomal defects. Many blood tests like dual, triple or quadruple marker test along with ultrasounds like nuchal translucency and anomaly scans are done to check foetal development and to check if the baby is at risk of suffering from any chromosomal abnormalities. The scores and results of these tests are used to decide if a mother needs to go for more invasive tests. Usually, an invasive test would involve going for an amniocentesis which involves taking a direct sample from the baby s amniotic fluid or Chorionic Villus Sampling(CVS sampling) that requires drawing blood or placental tissue from the placenta. Both these procedures increase one s chances of suffering from a miscarriage.
However, another way to check for genetic or chromosomal defects is to go for a non-invasive prenatal blood test. Here Dr Meghana Sarvaiya, Consultant Gynaecologist and obstetrician, Cloudnine Hospital, Mumbai, tells about this new diagnostic procedure.
What is non-invasive prenatal blood test?
Unlike invasive procedures like amniocentesis and CVS sampling, the non-invasive prenatal blood test is a simple blood test where blood is taken from the mother, and the baby s DNA is separated from it to check for genetic or chromosomal defects. This test is safer as the baby s DNA is naturally found in maternal blood.
What can the test do?
The test can check for chromosomal abnormalities like Down s syndrome, trisomy 14, 18 and other congenital conditions in the foetus.
When is this test done?
This test is not for every pregnant woman. Only mothers who fall into the high-risk category for having a baby with Down s syndrome or other chromosomal abnormalities is asked to go for this test if she isn t willing to go for an amniocentesis or CVS sampling.
How accurate is the test?
The accuracy of this test is also 99.9 percent. Still, an invasive test like amniocentesis can be more accurate, but it has a risk of miscarriage. All screening procedures, including this one, doesn t guarantee 100 percent result so take any major decision after careful consultations.
Image source: Shutterstock
