A new type of prenatal testing that is meant to find genetic flaws in a fetus can sometimes also reveal undiagnosed cancer in the expectant mother.
The findings were revealed in a study that involved eight women who had abnormal prenatal blood tests results first, but later assessment showed that their babies were normal. However when the mother’s DNA was reanalyzed, the anomalies were linked to cancer in each woman.
The scientists said in a report which was placed before a meeting of International Society for Prenatal Diagnosis in Washington, D.C., that prenatal challenges since its launch in the market in 2011 has thrown up both opportunities and challenges.
A prenatal blood test is a noninvasive form of blood tests which is meant to detect evidence of fetal abnormalities in the blood of a pregnant woman.
Doctors can detect genetic abnormalities like Down syndrome with a simple blood test rather than going for more invasive forms of investigation such as amniocentesis or chorionic villus sampling that can, in rare cases, induce miscarriages.
The latest study reveals that the tests can analyze both fetal and maternal DNA and can lead to surprising results. Diana Bianchi, executive director of the Mother-Infant Research Institute at Tufts Medical Center, Boston, said that when the tests came doctors were not aware that it could be used to detect evidence of cancer. It was something that was never thought.
Dr. Bianchi feels that though the non-invasive tests are very accurate, the latest finding underlines the need to double check any positive result with confirmation by an amniocentesis or chorionic villus sampling diagnostic test before considering termination of pregnancy. There is a probability that the initial test has nothing to do with the fetal condition.
The tests when introduced were recommended only for women who were at high risk of carrying a fetus with chromosomal aberrations. However, later they have been rapidly adopted by clinicians and patients.