Y Chromosome Maternal Blood Test
A blood test can be performed after 6 weeks of pregnancy. Determining the fetal gender enables families affected by genetic disorders to initiate early intervention.
What is the Y Chromosome Maternal Blood Test?
The Y Chromosome Maternal Serum Test is a non-invasive prenatal DNA testing technique (as opposed to traditional invasive methods like amniocentesis) used to assess the risk of fetal gender-related disorders and to confirm or exclude paternity. Utilizing advanced technology, it isolates fetal cell-free DNA fragments from maternal serum, amplifies these fragments millions or even tens of millions of times through DNA amplification techniques, and then detects the presence of male Y-chromosomal genetic material—specifically the SRY (Sex-determining Region Y) gene—using specific markers.
The Y chromosome (Y-Chromosome) is the only genetic material inherited exclusively from the biological father and is critical for embryonic development into a male. By comparing Y-chromosome markers, paternal lineage can be traced, as the Y chromosome is passed from grandfather to father, father to son, and so on.
During pregnancy, a small amount of fetal DNA crosses the placenta into the mother's bloodstream. This allows the isolation and analysis of trace fetal DNA from maternal blood to determine the status of the fetus's sex chromosomes.
Technical Features of the Y Chromosome Maternal Blood Test
Advances in technology have now rendered the testing process highly automated, enabling faster and more precise DNA extraction. Full automation across the entire testing process minimizes contamination risks, ensures standardized procedures, and significantly enhances testing stability, accuracy, and efficiency.
Early determination of fetal gender during pregnancy enables families at risk of genetic disorders to initiate timely intervention. For example, X-linked recessive genetic disorders (such as Fragile X Syndrome) are severe hereditary conditions that primarily affect male infants, with a 50% chance of inheritance. These disorders can lead to vision impairment, epilepsy, intellectual disabilities, and developmental delays. The Y Chromosome Maternal Blood Test identifies whether the fetus is male, allowing families to proactively seek prenatal genetic counseling and prepare for potential medical management.