One of the most popular books which deal with sex selection was written by Dr.Landrum Shettles. In this book, he outlines various ways in which parents can use different methods to determine the sex of their child. In particular, he focused on practices that would help persons who wish to conceive baby girls. However, the methods that he proposes are those that require little or no technology. The major aspect of sex selection that Dr.Shettles focused on was the fact that the male sperm are the ones that bear the Y chromosome and also that these sperm have the ability to swim faster than female sperm but that they also die more quickly.

His method seeks to improve chances of having a baby girl by preying on the weaknesses of the male sperm. One of the ways that he mentioned that this can be achieved is by ensuring that when an egg is released into the ovary, there are more X sperm present than Y sperm. If an X sperm fertilizes the egg, then a baby girl would be conceived. In order to do this, one must be aware of the times in which they are ovulating; this can be done by charting the basal body temperature. You should have sexual intercourse when the menstrual cycle ends but refrain from having sexual relations three days before ovulation occurs. Dr. Shettles also mentions that choosing positions that place the sperm near to the entrance of the vaginal canal would increase the chances of having a baby girl since the sperm would have to swim farther and they may have died by the time they arrive at the ovum. This method has been proven to be effective and is relatively low maintenance when compared to other methods of gender selection.