Boy or Girl? Fetal DNA Tests Often Spot On
Report Confirms Effectiveness of Using Mother's Blood to Detect Unborn Baby’s Gender, Paves Way for Alternatives to Invasive Tests
Fetal DNA Tests: Perspective
The findings confirm what experts in the field have known, says Joe Leigh Simpson, MD, professor of obstetrics and gynecology at Florida International University in Miami. "Many different labs can in fact verify when a male pregnancy exists. This helps to confirm that the next steps down the path are taken on some firm ground," he says.
He reviewed the findings for WebMD but wasn't involved in the research. He reports being on the scientific advisory board of BioDx, involved in cell-free DNA research, and RareCells.
He agrees that the hope is to use the fetal DNA test to rule out or identify certain conditions early in the pregnancy. ''There are a certain number of conditions in which a female would not be affected [typically], hemophilia being an example," he says.
Simpson says the issue of using the tests for ''family balancing'' is often brought up in debates about the use of the tests. For instance, a family has two boys and is hoping for a girl and decides to take a gender test.
In his experience, the number of people who are going to terminate a pregnancy simply based on the finding that the fetus is the ''wrong'' sex is not an issue, although it is a concern voiced by some experts.
"It's a bogeyman everyone raises but I'm not sure it's valid in America," Simpson tells WebMD.
The test will not likely replace more invasive tests such as amniocentesis in the near future to detect such conditions as Down syndrome, says Mary Norton, MD, professor of obstetrics and gynecology and director of perinatal research at Stanford University School of Medicine. She also reviewed the research.
A test of fetal DNA in maternal blood to detect Down syndrome is under development.
That is because the test for Down syndrome has limitations. The most likely role for the test, at least for the near future, she says, would be ''to identify those women at high enough risk [of carrying a fetus with a birth defect] to go on to amnio."
However, by doing that, she says, it will spare many other women who are deemed not high risk the expense, stress, discomfort, and risk of amnio, she says.