Gender Specific Sperm Separation

Gender Specific Sperm Separation Procedure

The desire to control the sex of the child prior to conception has been practiced since the very dawn of humanity and the social and cultural influences have been historically documented. 

Many patients have indicated the desire to influence the sex of their offspring through Selective Sperm Separation to restrict family size and minimize or avoid sex-linked genetic disorders.

The sperm sex selection procedure is effective, but not guaranteed to be 100% successful. It should be viewed as an option to increase the odds of having a desired child. This is because a man ejaculates millions of sperm and it takes only one to achieve pregnancy. Even with the stringent sex selection procedures, a few sperm of the undesired sex may contaminate the final selection. However, it may be more effective if combined with IVF and or pre-implantation genetic screening (PGS), since many eggs are exposed to a population of sex-selected sperm resulting in a higher number of embryos with the desired sex.  

Please Note: Your desire for a healthy child should outweigh your desire for a child of a desired sex. 

The sperm sex selection procedures have been used in many formats for more than 50 years. These procedures are based on differences in size, weight and how fast sperm move between the X chromosome bearing (female) and Y chromosome bearing (male) population of spermatozoa. These features are exploited by exposing a population sperm to either a physiologically controlled viscous media which enhances the differences in size and motility of sperm or the rate of settling when centrifuged through layers of physiologically controlled density gradient which enhances the differences in size and weight of sperm. Thus, the procedures do not alter the overall quality of sperm.

Gender Specific Sperm Separation Procedure for IUI or IVF

For male gender: Two-layer albumin column separation methods are employed. Semen is layered over the column and the motile sperm is allowed to migrate down to the bottom over time. The bottom layer is then washed, and the sperm concentrated for IUI or frozen in straws or vials for IVF.

For female gender: Multilayer density gradient methods are employed. Semen is layered over the column of 11 different concentrations of density gradient and centrifuge at 400 g for 25 minutes and the resulting sperm pellet is then washed and concentrated for IUI or frozen in straws or vials for IVF.

Reference:

• Erickson RJ. Sex selection via albumin column: 20 years of results. Hum Reprod 1974; 9: 1787-88
• Iizuka R, Kaneko S, Aoki and Kobayashi T. Sexing of human sperm by discontinuous Percoll density gradient and its clinical application. Hum Reprod 1987; 2: 573-75

Gender Specific Sperm Separation Procedure for ICSI

Motile sperm are collected by centrifuging over a density gradient  and layered over a column of 4 different concentrations of density gradient, and the sperm are allowed to self-select at 4⁰C.

For the male, the top layer is washed, concentrated and frozen in straws or vials for ICSI.

For the female, the bottom layer is washed, concentrated and frozen in straws or vials for ICSI.

Reference:

Cheung S, Elias R, Xie P, Rosenwaks Z, Palermo GD (2023) A non-randomized clinical trial to determine the safety and efficacy of a novel sperm sex selection technique. PLoS ONE 18(3): e0282216. https://doi.org/10.1371/journal.pone.0282216