The X and Y sperm display different characteristics. The female (X) sperm are larger, slower and live longer than the Y sperm while the male (Y) sperm appear to be favoured by the slightly acidic conditions in the vagina.

It’s because of this that some experts suggest that the timing and frequency of intercourse can have an effect on whether an X or Y sperm reaches and fertilizes the egg.

When: For a female baby, make love up to two to three days before ovulation, as only female sperm will survive long enough to reach the egg as it is released.

For a male baby it’s suggested that you make love on the day of, or just after, ovulation, as the faster male sperm will reach the ovum before the female sperm.

Frequency: For a female baby, it’s suggested that you make love fairly frequently as this lowers the proportion of male sperm in the semen.

For a male baby, make love infrequently, as this will increase the proportion of male sperm.

Diet: This might also be a determining factor. The idea is that X and Y sperms respond differently to the amounts of sodium, potassium and calcium in the mother’s body.

Male (Y) sperms like salt. So a diet for a boy may mean avoiding cheese, milk and fish with edible bones, and restricting eggs and bread. Add orange juice, ham, beef and yeast extract, eat plenty of salt and take potassium tablets. For a girl, cut your sodium intake, lessen potassium and increase calcium. Eat less salt and drink more milk. This is certainly not an exact science, so results can’t be guaranteed.