Can I choose a boy or girl? Is natural gender selection feasible?

Proponents of gender selection in babies believe that it gives the couple a choice in choosing their child's gender.

Opponents question the morality of such a practice. Gender selection is not allowed in Assisted Reproductive Techniques in many countries.

The Department of Obstetrics & Gynaecology at KK Women's and Children's Hospital (KKH), a member of the SingHealth group, examines some natural techniques that have been suggested. However, it must be noted that these methods are not scientifically proven.

How is a baby's gender determined?

A baby is conceived from the fertilization of a sperm and an egg. The egg can only carry an X chromosome while a sperm can possess either a X or Y chromosome from the father. If can X-carrying sperm fertilizes the egg, a baby girl (XX) will be conceived. If a Y-carrying sperm fertilizes the egg, a baby boy (XY) will be conceived. Therefore, it is evident that the father "influences" the gender of his offspring.

Scientific basis for gender selection in babies

One of the theories suggested is that the sperm with the Y chromosome, known as the androsperm (resulting in a male offspring), is tiny and fragile but fast. On the contrary, the sperm with the X chromosome, known as the gynosperm (resulting in a female offspring), is larger and hardier with a longer lifespan, but is sluggish. Therefore, the male sperm would race to meet the egg enthusiastically than the female sperm. But they have a short lifespan and would not be able to survive in an acidic vaginal environment.

Gender section options — Natural methods

1. Shettles method (for male offspring)

Time the intercourse to as close to the ovulation as possible — preferably within 24 hours before ovulation. There should be a period of abstinence of about 3-4 days in order to maximize the number of male sperms produced. Penetration at the moment of ejaculation should be as deep as possible, e.g. rear entry. This ensures that the sperms are deposited above the neck of the cervix, where the vaginal environment is more alkaline and thus, more favourable for the male sperms to survive. This increases the chances of the male sperms reaching the egg faster than the female sperms.

2. Shettles method (for female offspring)

The converse to the above mentioned will hold true. Timing the intercourse two days prior to ovulation will ensure that only the female sperms will survive till fertilization. Shallow penetration, e.g. man-on-top will ensure that the sperms are deposited at the mouth of the cervix. This favours the survival of the female sperms. Some have advocated avoiding a female orgasm as this keeps the vaginal environment highly acidic.

Gender selection kits

Many of such kits are now available and can be found on the Internet. However, they can be costly. They aim to help guide the couples choose the gender of their child over one ovulatory cycle, by following the instructions attached. Most are based on the Shettles method and comprise of various ovulation predictor test sticks aided by application of a vaginal douche to help make the environment more suitable for either a male or female sperm.

Gender selection myths

As in all things, various myths do exist and have no scientific basis at all, other than being handed down from generations within the family. They included a whole host of things such as the choice of diet, sleeping positions, having intercourse on certain calendar days and for either of the partner to reach an orgasm first. These are unproven and should be read only purely for the sake of interest.

Ref: M19