Abstract

PIP: The sex ratio and the possibility of the determination of sex prior to conception are discussed. Fluorescence microscopic examination of spermatozoa stained with fluorochrome quinacrine has revealed that the smaller-headed sperm contains the Y-chromosome. The frequency of Y-bearing spermatozoa in human samples has been reported to be 66%. A differential filtration frequency of 96-98% for passage of Y-sperm into optimal cervical mucus has also been reported. The average sex ratio is about 100 females:105-107 males, though ratios at least as high as 100:150 have been found in certain cultures. The chances for conceiving a male offspring are highest when the cervical milieu is optimal for conception. Since male siblings are often valued more than females in many cultures and religions, the ability to select the sex of offspring could have salutary effects on problems posed by high birthrates.