Shettles Method

X is girl Y is boy The Shettles Method is based on the belief that X sperm and Y sperm behave in different ways. According to the method, X sperm is typically slower but live longer in a woman’s body, while Y sperm are faster, but have shorter life spans. Therefore, the way to enhance one sex’s likelihood over the other is to time intercourse accordingly. According to the Shettles Method, a couple that wished to conceive a girl would ideally time intercourse to occur 3-4 days prior to ovulation. This would allow the Y-bearing sperm time to die off, leaving predominantly X-bearing sperm at the time ovulation occurs. For those wishing to conceive a boy, the opposite tactic is advised, and couples are instructed to time intercourse to occur as close as possible to the time of ovulation.