Prenatal Testing::Cervical swab may be enough

Cervical swab may be enough for prenatal testing

Fri May 27, 2:13 PM ET

Researchers in Australia have worked out a way to isolate single cells from a fetus in the cervical mucus of a pregnant woman, and to use these cells to test for genetic abnormalities.

According to Dr. Mandy G. Katz-Jaffe and colleagues at Monash University in Melbourne, current methods for detecting chromosomal abnormalities in fetuses have various limitations or drawbacks. For example, amniocentesis carries a risk of miscarriage. Some screening tests give a high number of high false-positive results, while others are labor-intensive.

In the medical publication BJOG: an International Journal of Obstetrics and Gynecology, the researchers describe their process for isolating fetal cells from the cervical mucus of women between 7 and 10 weeks into pregnancy.

Basically it involves using an enzyme to free up the cells, and fluorescent antibodies to tag the fetal cells.

Cells can then be checked for the number of copies of chromosome 21 -- two being normal, three indicating Down's syndrome.

Though further validation on larger sample sizes are required, the researchers say their results "are a proof of principle" that fetal cells isolated from cervical mucus can be used for genetic diagnosis.

The team has also developed other profiling systems to diagnose other chromosomal anomalies as well as single gene disorders.

A system like theirs, they write, could be used to test both high- and low-risk pregnancies during the first trimester, "resulting in earlier reassurance for the couple or the option of a first trimester termination."

---REUTERS