Sperm Gender Check

The ratio of X-to-Y sperm varies greatly across individuals.

Sub Link: Do these ratios hold true

The table below shows the percentages of X- and Y-bearing spermatozoa in semen samples from 50 different men (participants).

IndividualparticipantY Sperm % X sperm % IndividualparticipantY Sperm %X sperm %
15644264852
26337274357
33763284852
43763294357
54555305347
63961313367
74159324852
84852334060
93466344159
105545354357
114852364951
125941372278
134456383169
145248394555
155941405743
164852414852
174852424456
184951434060
195050443070
204951454456
215149464456
225149474357
235149483664
245248494654
255050504654

The table above shows the high degree of variation that exists between 50 individuals when it comes to X-to-Y sperm ratios. For example, when comparing results for participant 2 (63% Y, 37% X) and participant 44 (30% Y, 70% X), it is clear that participant 2 would be expected to have a much higher probability of producing male (Y) children than participant 44, because participant 2 has 63% Y-bearing sperm in his semen vs. 30% in participant 44. Likewise, participant 44 would be expected to have a much higher probability of producing female (X) children.

Do These Ratios Hold True

But do these ratios hold true from ejaculate to ejaculate?

Research indicates that a given individual’s X-to-Y sperm ratio remains consistent from sample to sample: it appears to be set at the genetic level. Therefore, although the number of spermatozoa and their motility may vary from ejaculate to ejaculate, the ratio of X sperm to Y sperm remains constant for each individual.

There is therefore great value for prospective parents in understanding your own personal X-to-Y sperm ratios. The SpermGenderCheck can provide you with the ratio of X-to-Y sperm in your semen sample, helping you to better anticipate the outcome and/or likelihood of success of any gender selection process you may be considering.

Reference:

  • Jeyendran RS, Graham J, Tharma S, Ivanovic M, Levrant S, Ozornek HM, Fiddler MB. Individual variation of the percentage of Y-chromosome bearing sperm content in human ejaculates. Syst Biol Reprod Med. 2021; 67:5, 395-398