Non-Invasive Fetal Sex Determination

This non-invasive test determines the sex of the fetus by detecting Y-chromosome (SRY gene) DNA fragments in a maternal blood sample. It requires only a routine blood draw and can be performed from early in pregnancy, giving expectant parents an early and reliable answer without any invasive procedure. The same SRY detection method is also offered as a standalone test, for example for sport eligibility verification.

Early fetal sex determination uses the same cell-free fetal DNA principle as non-invasive prenatal screening. A maternal blood sample is analysed for the presence of Y-chromosome-specific sequences, most notably the SRY gene. Detection of Y-chromosome DNA indicates a male fetus; its absence indicates a female fetus. Because fetal DNA is present in maternal blood from early in pregnancy, the test can give a result well before sex is visible on ultrasound. The laboratory performs the analysis from a standard venous blood draw with no risk to the pregnancy. The same SRY-detection assay is also available as a standalone genetic test outside of pregnancy contexts. The test is intended for expectant parents who want to know fetal sex early, and for situations where a clinical reason makes early sex determination useful, such as families with a history of sex-linked genetic conditions.