New prenatal screening test drastically decreases risks


New procedures for prenatal screening can greatly reduce the need for pregnant women to undergo risky invasive testing for genetic abnormalities. Image from Wikimedia Commons.

A new testing procedure can greatly cut the risk involved for pregnant women in prenatal screening tests for genetic abnormalities. Screening for developmental abnormalities while a fetus is gestating carries an inherent risk of triggering a miscarriage. The new procedure cuts the risk to near zero.

Testing procedure could reduce invasive tests

A study from the Li Ka Shing Institute of Health Sciences in Hong Kong at the Chinese University of Hong Kong has discovered a new method of screening for genetic abnormalities such as Down syndrome during pregnancy, according to ABC. The study was published in the British Medical Journal. The test uses the latest in gene sequencing technology, and could mean far fewer women have to undergo invasive tests to collect genetic material from infants. It was discovered in 1997 that fetuses release their genetic information into the mother’s bloodstream. Using modern gene sequencing equipment, the team at the Li Ka Shing Institute, headed by Dr. Rossa Chiu, was able to screen for genetic abnormalities with about 98 percent accuracy with only a blood sample.

Current tests have risk of miscarriage

The most reliable tests are amniocentesis and Chorionic Villus Sampling, or CVS. Amniocentesis collects a sample by inserting a needle into the amniotic sac to extract genetic material, whereas CVS takes a sample from the placenta. Both tests carry a 1 percent or less risk of triggering a miscarriage, which is more than some pregnant women are willing to bear. Prenatal screening tests are most often used to detect genetic defects such as Down syndrome, according to WebMD. Down syndrome is caused by having three copies, instead of two, of chromosome 21.

Not ready for widespread use

The test is not ready for widespread use, as the technology for the proper gene sequencing isn’t widely available yet. Down syndrome occurs in less than 0.7 percent of live births. However, most confirmations of Down syndrome lead to an abortion in many countries, including the United States.




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