January 4, 2012
First-trimester Blood Test Reveals Fetal Gender
A new South Korean study could pave the way for a simple, non-invasive test that predicts fetal gender as early as the first trimester of pregnancy.
The researchers discovered that various ratios of two enzymes (DYS14/GAPDH), which can be extracted from a pregnant mother's blood, indicate whether the baby will be a boy or a girl.
"Generally, early fetal gender determination has been performed by invasive procedures such as chorionic villus sampling or amniocentesis. However, these invasive procedures still carry a one to two percent risk of miscarriage and cannot be performed until 11 weeks of gestation,” said Dr. Hyun Mee Ryu, a researcher involved in the study from Cheil General Hospital and Women's Healthcare Center at the KwanDong University School of Medicine in Seoul, Korea.
“Moreover, reliable determination of fetal gender using ultrasonography cannot be performed in the first trimester, because the development of external genitalia is not complete.”
"Therefore, this can reduce the need for invasive procedures in pregnant women carrying an X-linked chromosomal abnormality and clarify inconclusive readings by ultrasound."
Ryu and colleagues collected maternal plasma from 203 women during their first trimester of pregnancy, and confirmed the presence of circulating fetal DNA by a quantitative methylation-specific polymerase chain reaction of U-PDE9A.
Multiplex real-time polymerase chain reaction was used to simultaneously quantify the amount of DYS14 and GAPDH in maternal plasma. The results were confirmed by phenotype at birth.
"Although more work must be done before such a test is widely available, this paper does show it is possible to predict the sex of a child as early as the first few weeks after conception," said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal, which published the study in January.
"At present, parents are sometimes given the wrong information about the sex of their unborn child; this test should prove helpful in resolving any uncertainties of today's ultrasound observations."
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