3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> Boy or girl

Boy or girl

You may have a clear idea of what sex you would like your baby to be. Perhaps you want a baby of the opposite sex to your first child - or you may have medical reasons. In some countries, such as the United Kingdom, scientific methods of sex selection are legal only in cases of genetically inherited diseases so, if your reasons are a matter of preference, try some of the natural methods described here.

What are little boys and girls made of?

Every egg and sperm contains 23 chromosomes. Of these, one chromosome is a sex chromosome. Each egg contains one X chromosome, while every sperm contains either one X or one Y chromosome. If the sperm which fertilizes the egg contains a Y chromosome, the baby will be a boy; if it contains an X chromosome, the baby will be a girl. Left to nature, there is a good balance of the sexes: about 103 boys are born for every 100 girls. However, there is a real danger that the scientific methods of sex selection currently being developed will upset this natural balance.

Scientific sex selection

There are currently two main scientific methods of sex selection:
Pre-implantation genetic diagnosis (PGD) This procedure involves removing a cell from the developing embryo conceived through IVF for genetic testing to identify whether it has X or Y chromosomes.

Sperm sorting This involves separating male and female sperm either by spinning live sperm in a device called a centrifuge or by using a fluorescent dye to detect the X and Y chromosomes in the semen sample.

In some countries, such as the United Kingdom, PGD is illegal except where there is a high risk of a serious genetic disease being passed on (for example, haemophilia affects only boys, so if a couple is at risk of passing on a gene for this condition, a doctor could recommend sex selection methods to ensure they conceive a girl, see right). Fertility procedures involving frozen sperm or live embryos are regulated by the Human Fertilization and Embryology Authority (HFEA). Fresh sperm do not come under its jurisdiction and can currently be sorted for sex selection, although not at any clinic licensed by the HFEA.

Natural sex selection

There are various natural methods that you can use to try to influence the sex of your baby. You can choose one that suits you or try a combination of them. However, even if you get the result you want, you will never know whether the method worked or if it was just chance.

Timing intercourse

One of the most popular methods is timing when you have sex, which is based on the theory that male sperm swim faster than female sperm but die sooner.
For a boy Abstain from sex for 2-3 days before you ovulate, then have intercourse as soon after as possible so the speedier male sperm will reach the egg first.
For a girl Have sex 2-3 days before ovulation, so that the male sperm will have died by the time the egg is released, and the longer-living female sperm will have a greater chance of reaching the egg.

Acid or alkaline?

Male sperm are said to prefer an alkaline environment while female sperm prefer an acidic environment. It should therefore be possible to influence the sex of your baby by making your vagina more acid or more alkaline. You should do this about half an hour before you have intercourse.

For a boy Flush your vagina with a solution of bicarbonate of soda (alkaline).

For a girlFlush your vagina with diluted lemon juice or vinegar (acid).


Some women swear by dietary methods. For a boy Eat foods rich in sodium and potassium, for example, meat, dried and salted fish, rice, pasta, potatoes and beans, and certain fruits and vegetables such as bananas, apricots and celery. :or a girl Eat foods rich in magnesium as well as calcium, for example, dairy products, eggs, nuts, soya jeans, leafy green vegetables and fresh fruit juice.