Featured Research

from universities, journals, and other organizations

Tests that use DNA from mother’s blood to determine sex of fetus often effective

Date:
August 9, 2011
Source:
JAMA and Archives Journals
Summary:
As a noninvasive method of determining the sex of a fetus, tests using cell-free fetal DNA obtained from the mother's blood after 7 weeks gestation performed well, while urine-based tests appear to be unreliable, according to a review and analysis of previous studies.

As a noninvasive method of determining the sex of a fetus, tests using cell-free fetal DNA obtained from the mother's blood after 7 weeks gestation performed well, while urine-based tests appear to be unreliable, according to a review and analysis of previous studies, reported in the August 10 issue of JAMA.

Noninvasive prenatal determination of fetal sex could provide an important alternative to invasive cytogenetic determination, which is currently the gold standard for determining sex and single-gene disorders. Amniocentesis has small but measurable rates of procedure-related pregnancy loss; and sonography can be performed as early as 11 weeks' gestation to determine fetal sex, although not reliably, according to background information in the article. "The availability of a reliable noninvasive alternative to determine fetal sex would reduce unintended fetal losses and would presumably be welcomed by pregnant women carrying fetuses at risk for disorders," the authors write.

Using cell-free fetal DNA as a noninvasive method for prenatal determination of fetal sex provides an alternative to invasive techniques for some heritable disorders. In some countries, such as the Netherlands, the United Kingdom, France, and Spain, this testing has already transitioned to routine clinical care despite the absence of a formal assessment of its performance. "More recently, companies have begun offering this technology directly to the consumer over the Internet. The tests are marketed for nonmedical use to curious parents-to-be with promises in some cases of accuracy as high as 95 percent to 99 percent at as early as 5 to 7 weeks' gestation," according to background information in the article.

Stephanie A. Devaney, Ph.D., of the National Institutes of Health, Bethesda, Md., and colleagues performed a systematic review and meta-analysis of previous research to examine the analytic validity of cell-free fetal DNA testing, which describes the test's ability to detect Y chromosome sequences within maternal samples, as well as the clinical validity of the test, as indicated by its ability to correctly identify fetal sex. The researchers selected 57 studies (which included 80 data sets [representing 3,524 male-bearing pregnancies and 3,017 female-bearing pregnancies]) for inclusion in the analysis.

The researchers found that the overall performance of the tests had sensitivity of 95.4 percent, specificity of 98.6 percent, positive predictive value, 98.8 percent, and negative predictive value, 94.8 percent. Performance was high using maternal blood. DNA methodology and gestational age had the largest effects on test performance, with real-time quantitative polymerase chain reaction (RTQ-PCR) outperforming conventional PCR. Test performance was high if performed using RTQ-PCR on a blood sample taken at a time during pregnancy when sufficient cell-free fetal DNA was present (7 weeks' gestation or later), with the best performance after 20 weeks' gestation. Testing performed prior to 7 weeks' gestation using blood, and all tests using urine, were found unreliable.

"The improved performance with later gestation is likely attributable to the increased concentration of cell-free fetal DNA within maternal blood as the fetus and placenta develop. This would explain the poor performance of the test prior to 7 weeks' gestation and the near-perfect performance in the third trimester," the authors write.

The researchers suggest that this "technology can be useful in clinical settings for early detection of fetuses at risk for sex-linked disorders requiring follow-up testing."


Story Source:

The above story is based on materials provided by JAMA and Archives Journals. Note: Materials may be edited for content and length.


Journal Reference:

  1. Stephanie A. Devaney, Glenn E. Palomaki, Joan A. Scott, Diana W. Bianchi. Noninvasive Fetal Sex Determination Using Cell-Free Fetal DNA: A Systematic Review and Meta-analysis. JAMA, 2011; 306 (6): 627-636 DOI: 10.1001/jama.2011.1114

Cite This Page:

JAMA and Archives Journals. "Tests that use DNA from mother’s blood to determine sex of fetus often effective." ScienceDaily. ScienceDaily, 9 August 2011. <www.sciencedaily.com/releases/2011/08/110809162000.htm>.
JAMA and Archives Journals. (2011, August 9). Tests that use DNA from mother’s blood to determine sex of fetus often effective. ScienceDaily. Retrieved August 28, 2014 from www.sciencedaily.com/releases/2011/08/110809162000.htm
JAMA and Archives Journals. "Tests that use DNA from mother’s blood to determine sex of fetus often effective." ScienceDaily. www.sciencedaily.com/releases/2011/08/110809162000.htm (accessed August 28, 2014).

Share This




More Health & Medicine News

Thursday, August 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
Powered by NewsLook.com
Who Could Be Burnt by WHO's E-Cigs Move?

Who Could Be Burnt by WHO's E-Cigs Move?

Reuters - Business Video Online (Aug. 28, 2014) The World Health Organisation has called for the regulation of electronic cigarettes as both tobacco and medical products. Ciara Lee looks at the impact of the move on the tobacco industry. Video provided by Reuters
Powered by NewsLook.com
CDC Director On Ebola Outbreak: 'It's Worse Than I Feared'

CDC Director On Ebola Outbreak: 'It's Worse Than I Feared'

Newsy (Aug. 28, 2014) CDC director Tom Frieden says the Ebola outbreak is even worse than he feared. But he also said there's still hope to contain it. Video provided by Newsy
Powered by NewsLook.com
How A 'Rule Of Thumb' Could Slow Down Drinking

How A 'Rule Of Thumb' Could Slow Down Drinking

Newsy (Aug. 28, 2014) A study suggests people who follow a "rule of thumb" when pouring wine dispense less than those who don't have a particular amount in mind. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins