An easy blood test can determine fetal gender in the first twelve weeks of pregnancy, researchers said Tuesday.

The findings in a study by South Korean researchers could lead to a non-invasive test that would let soon-to-be mothers know the sex of their baby as early as the first trimester and such tests would be the first of its kind, according to a statement.

Researchers found that several ratios of two enzymes (DYS14/GAPDH) that are extracted from a pregnant woman’s blood indicated whether the baby will be a boy or a girl.

Early fetal gender determination does exist, however it is performed by invasive procedures like chorionic villus sampling or amniocentesis, both requiring either a sample of placental tissue or fluid from the amniotic sac. The current procedures also carry a one to two percent risk of miscarriage, and generally cannot be performed until 11 weeks of gestation.

Another reliable non-invasive determination of fetal gender using ultrasonography cannot be performed in the first trimester because the fetal development of external genitalia is not complete, and furthermore the current results show that the new procedure can reduce the need for invasive procedures in pregnant women carrying an X-linked chromosomal abnormality and aid in clarifying readings by ultrasound, researchers said.

Hyun Mee Ryu, a researcher from the Department of Obstetrics and Gynecology at Cheil General Hospital and Women's Healthcare Center at the KwanDong University School of Medicine in Seoul said that he and his team had collected maternal plasma from 203 women during the first trimester of pregnancy and predicted the fetal DNA by measuring the methylation-specific polymerase chain reaction of U-PDE9A.

Afterwards, the multiplex polymerase chain reaction was used to simultaneously quantify the amount of DYS14 and GAPDH in maternal blood, and the results were later confirmed by the 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, Editor-in-Chief of The FASEB Journal, the journal in which the study was published, in a statement.

"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," Weissmann added.