You may have heard that the odds of conceiving a boy or a girl is about This method details when and how to have sexual intercourse in order to conceive either a boy or girl. Related: How to increase your chances of getting pregnant. The Shettles method has been around since the s. It was developed by Landrum B. Shettles, a physician living in the United States.
Shettles studied sperm, the timing of intercourse, and other factors, like sexual position and the pH of body fluids, to determine what might have an effect on which sperm reach the egg first. After all, the sperm that fertilizes the egg is ultimately what determines the sex of the baby. More on that process in a minute. From his research, Shettles developed a method that takes all these factors into account. As you can imagine, this information was in high demand.
The sex of your baby is determined in the most basic way at the moment when the sperm meets the egg. Men, on the other hand, produce millions of sperm during ejaculation. Roughly half of these sperm may be coded with the X chromosome while the other half carry the Y chromosome. If the sperm that fertilizes the egg carries the Y chromosome, the resulting baby will likely inherit XY, which we associate with being a boy.
If the sperm that fertilizes the egg carries the X chromosome, the resulting baby will likely inherit XX, meaning a girl. Of course this depends on the most general understandings of what sex is and how it is defined. Shettles studied sperm cells to observe their differences. What he theorized based on his observations is that Y male sperm are lighter, smaller, and have round heads. On the flip side, X female sperm are heavier, larger, and have oval-shaped heads. Interestingly, he also studied sperm in some rare cases where men had fathered either mostly male or mostly female children.
In the cases where the men had mostly male kids, Shettles discovered that the men had far more Y sperm than X sperm. And the opposite also rang true for the men who had mostly female kids. In addition to physical differences, Shettles believed that male sperm tend to swim more quickly in alkaline environments, like in the cervix and uterus. And female sperm tend to survive longer in the acidic conditions of the vaginal canal. As a result, the actual method for conceiving a girl or boy via the Shettles method is dictated by timing and environmental conditions that help favor male or female sperm.
