Life Science Encyclopedia

Concept

The Shettles Method is a child conception idea that is reputed to help determine a baby's sex, developed by Landrum B. Shettles in the 1960s.

By following the various methods outlined by Dr. Shettles in the book "How to Choose the Sex of Your Baby" it is proposed that a couple can determine whether they will have a boy or a girl. Proponents claim between 75 and 90 percent effectiveness, but experts do not agree that the method works.

According to the theory ,male (Y) sperm are faster but more fragile than female (X) sperm. The Shettles method aims to exploit the longevity factor, as opposed to the Ericsson method where the semen is deposited outside the woman and time is given for the fast/slow swimmers to separate before artificial insemination.

Timing of Intercourse

In order to have a boy insemination should occur as close as possible to the moment of ovulation so that the faster, Y-sperm arrive first and achieve conception, according to the theory. When seeking a girl insemination the couple should seek to have sex 2½ to 3 days before ovulation.

Sexual Position

Shallow penetration coupled with the sperm deposited close to the entrance favors female conception because the area is more acidic, which inhibits the weaker Y sperm, according to the theory. To allow the Y sperm to reach the egg first (which supposedly moves at a faster rate), deeper penetration should be sought, to deposit the sperm at the least acidic area near the uterus opening. Rear entry during intercourse is recommended.

Orgasms

Orgasms favor male sperm because they make the vaginal environment more alkaline. Acidic environments harm Y sperm, according to the theory, making conception of a girl more likely.