Sperm Spinning for Gender Selection

I was recently told about sperm-spinning for gender selection. Please explain what it is and if there is evidence that it works.


This test is called the Percoll density gradient centrifugation procedure. It is a costly, time consuming method for separating the X (female) from the Y (male) sperm. This procedure can be used to assist a couple with a family history of sex-linked disorders.

After spinning, the X-bearing sperm are said to be found in greater numbers at the bottom while the Y sperm may be closer to the surface. Several reports suggest separation efficiencies of over 77 percent.

It appears that the difference in sperm head dimension or motility facilitate the separation of X- and Y-bearing sperm, but supporting data are inconsistent. In one study, sperm derived from the bottom (X) fraction had a threefold higher percent motility when compared with sperm from the top (Y) fraction. The results suggest that bottom (X) fraction sperm had higher motility, progression, and hyperactivation when compared with top (Y) fraction sperm.

I hope that was not more than you wanted to know about sperm spinning.

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