Submitted to: Manual of Assisted Reproduction
Publication Type: Book / Chapter
Publication Acceptance Date: September 12, 1996
Publication Date: N/A
Technical Abstract: Preselection for sex in man and animals has occupied the imagination of mankind ever since the beginning of modern civilization. Theories abound as to how one can alter the sex of offspring. Early philosophers suggested various body positions during intercourse could give a child of one sex or the other. Still others suggested that parts of the male genital anatomy produced sperm specific to one sex or the other. In animals, numerous theories have been investigated resulting in a significant body of literature in which claims for skewing of the sex ratio are common place, yet little if any verification has been offered to support the various claims. Many of these protocols developed for animals involved an attempt to use one of the physical sperm measurements (size, shape, swimming speed, surface antigen etc.) as markers specific for one sex or the other on which to base the separation technique. None of the protocols based on these proposed markers of X or Y sperm has been shown to skew the sex ratio to any extent. The reader is guided to reviews which describe many of the "physical separation methods" in more detail than is possible here.