NRL News

New England Journal of Medicine study could spur call for wider use of prenatal genetic scanning

by | Dec 6, 2012

By Dave Andrusko

A nationwide study of 4,400 women published in Thursday’s New England Journal of Medicine found that scanning the genes of unborn babies “reveals far more about potential health risks than current prenatal testing does,” according to Marilynn Marchione, Chief Medical Writer for the Associated Press.

The study, led by Dr. Uma Reddy of the National Institute of Child Health and Human Development, found that 6% of babies “declared normal” by traditional prenatal testing were found to have genetic abnormalities.

An accompany editorial, written by Dr. Lorraine Dugoff, a University of Pennsylvania high-risk pregnancy specialist, argues “that gene testing should become the standard of care when a structural problem is suggested by ultrasound,” Marchione reports.

Dr. Susan Klugman, director of reproductive genetics at New York’s Montefiore Medical Center, which enrolled 300 women into the study, told AP, “We can never guarantee the perfect baby but if they want everything done, this is a test that can tell a lot more.”

The “gene flaws can cause anything from minor defects such as a club foot to more serious ones such as mental retardation, heart problems and fatal diseases,” Marchione writes.

Clearly the specter of even more abortions was on researchers’ minds. “This isn’t done just so people can terminate pregnancies,” because many choose to continue them even if a problem is found, said Dr. Ronald Wapner, reproductive genetics chief at Columbia University Medical Center in New York. “We’re better able to give lots and lots of women more information about what’s causing the problem and what the prognosis is and what special care their child might need.”

According to the story, an ultrasound exam or a blood test screening “can flag some common abnormalities such as Down syndrome, but these are not conclusive.” Further testing includes either amniocentesis or chorionic villus sampling.

The “advance” provided by gene scanning is that it can “spot hundreds of abnormalities and far smaller defects” than the “eyeball method” where doctors look through a microscope at samples of cells taken from the baby.

The study compared both methods for the 4,400 women. Marchione explains that

“Half of the moms were at higher risk because they were over 35. One-fifth had screening tests suggesting Down syndrome. One-fourth had ultrasounds suggesting structural abnormalities. Others sought screening for other reasons.

“’Some did it for anxiety — they just wanted more information about their child,’ [Dr. Ronald] Wapner said.

“Of women whose ultrasounds showed a possible structural defect but whose fetuses were called normal by the visual chromosome exam, gene testing found problems in 6 percent — one out of 17.”

Categories: Genetic Testing