Sperm Gender Check

Disparity in the Gender Specific Sperm in Human Ejaculates

The sperm separation techniques to promote fraction with greater purity of desired sperm type than the original sample have often yielded unreliable pregnancy outcomes.

Many reports suggest that the man does not produce equal number of X sperm or Y sperm based on using non-specific methods to differentiate between the X and Y sperm. 

We have developed a very specific real-time polymerase chain reaction (qPCR) with unique primers to determine the ratio of X and Y sperm from 50 randomly selected men which confirmed that there is truly a difference among the two types of sperm in an ejaculate. We found that the Y- sperm ranged from a low of 23% to a high of 63%, confirming the earlier assumption (Jeyendran et al., 2021).

For example, if an individual having a greater preponderance of X- sperm in his ejaculate were to be subjected to a Y-enrichment procedure, it is unlikely of conceiving a male would increase beyond the anticipated 50:50 level and vice versa.

It has been reported that men with more brothers had a higher probability of having sons and those with more sisters had a higher probability of having daughters. An increase of Y sperm in men with only sons (>3) or the X sperm in men with only daughters (>3) has been reported. 

Please Note: Anecdotally you have heard of families having only sons or daughters and may be true to some extent

Thus, it is advisable to determine the percent of X- and Y- sperm in an ejaculate prior to and/or following gender based sperm selection procedure to assess the odds of increasing the desired outcome.

We do provide services to determine the percent of X- and Y- sperm. 


  • Jeyendran et al., (2021) Individual variation of the percentage of Y-chromosome bearing sperm content in human ejaculates, Systems Biology in Reproductive Medicine, 67:5, 395-398, DOI: 10.1080/19396368.2021.1942589