Use of a fertility calculator does not increase the odds of conceiving a boy, according to HealthTap. Selection of sex of the embryo is essentially random and depends on whether the sperm that fertilizes the egg is carrying an X or a Y chromosome. The only way to ensure that the embryo is male is to use in vitro fertilization and preimplantation genetic diagnosis.Continue Reading
There is no functional or morphological difference between sperm carrying X or Y chromosomes, reports PubMed Central. The idea that there is a difference was raised by Dr. Shettles in the 1960s, but other researchers have proven that it is completely untrue.
The idea that using a fertility calculator to time intercourse in relationship to ovulation in order to preferentially conceive a boy or a girl was invented by Dr. Shettles, says BabyMed. The concept is based on the incorrect idea that sperm carrying Y chromosomes are faster but die more quickly than sperm carrying X chromosomes. Therefore, having sex on the day of ovulation was thought to be more likely to produce a boy because the faster Y chromosomes can get to the egg first. Having sex a day or two before ovulation favors producing a girl because the Y chromosomes die off before the egg arrives.Learn more about Pregnancy