| Summary: The Y-producing (male) sperm are smaller than the X-producing (female) sperm thus making the Y sperm faster but weaker than the X sperm. Since the X sperm are stronger than the Y sperm they are more resistant to various forms of stress. With these observations Dr. Shettles concludes that the faster, Y sperm will be most likely to reach the egg first and fertilize it when intercourse occurs at or near the time of ovulation. Vaginal secretions around ovulation are also most alkaline and thus most favorable to the Y sperm. The larger and more resistant, X sperm are most likely to fertilize the egg when intercourse takes place more than a day or two before ovulation, when secretions are still more acidic and thus most likely to eliminate the less resistant Y sperm. |