Blood test predicts fetus’s gender at 7 weeks
Posted August 10, 2011 11:30 am.
This article is more than 5 years old.
A blood test can detect the sex of a fetus as early as seven weeks into a woman’s pregnancy, which is much earlier than conventional methods, according to new research analysis.
The new review, published in Wednesday’s Journal of the American Medical Association, analyzed 57 studies involving more than 6,000 pregnancies and found that the blood test is more than 95 per cent accurate at determining the sex of a fetus at least seven weeks into a pregnancy. Reliability of the test increases further into the pregnancy, the researchers wrote.
The sex of a fetus can be determined starting at about 10 weeks using conventional procedures. Tests using a pregnant woman’s urine or blood before seven weeks of pregnancy were not reliable, the researchers found.
The analyzed test works by detecting fetal DNA in a pregnant woman’s blood. The sex of the fetus can be determined if the male Y chromosome is present, which indicates that the mother is carrying a male fetus. But if none is found, the fetus is female.
Such a test may provide an alternative to more invasive techniques that determine the sex of a fetus and some heritable disorders but pose a small risk of miscarriage.
The study also noted that availability of the test could raise ethical concerns if couples abort a pregnancy if the fetus is not the sex of their choice.
It also said that many of the studies reviewed were small so testing under highly controlled conditions would be beneficial.
Tests that companies sell directly to consumers were not analyzed in the review.
With files from The Associated Press
