“Bring forth men-children only,” Macbeth urged his wife. If he were offering the same advice in 2008, he would have had to add: “Have muesli for breakfast.”
New research suggesting that women increase their chances of having boys if they eat cereal for breakfast is the latest bizarre twist in a scientific debate that has been raging for centuries.
The study, in the journal Proceedings of the Royal Society B: Biological Sciences, also suggested that women increased their chances of giving birth to boys if they piled on the calories at the time of conception.
Could the faddish eating habits of women in industrialised countries explain that which has been puzzling scientists — the slight but steady decline in the proportion of males born in those countries?
The raw research statistics are not earth-shattering. Women who have had boys were consuming an average of 2,413 calories a day at the time they conceived, compared with the 2,283 calories for those who have had girls.
It is hard to imagine women desperate for a son scoffing an extra muffin a day to boost their chances.
Father of the child
Previous diet-related investigations in this field have focused on the father — it being an established fact that the gender of the baby is decided by whether the egg is fertilised with the X- or the Y-chromosome.
One study, for example, found that a diet rich in potassium (meat, bananas) boosted the Y-chromosome count and hence the likelihood of fathering boys.
Conversely, a diet rich in magnesium (soya beans, green vegetables) tipped the balance in favour of girls.
And diet is only one of the elements that have to be factored into the equation.
Since time immemorial, all kinds of scientific and pseudo-scientific evidence, not to mention old wives’ tales, have been invoked to predict the sex of children.
The Chinese have been using astrological charts for the purpose for more than a 1,000 years.
Even the animal kingdom — alpha females in some species produce a higher proportion of male offspring — has been scoured for clues.
For parents desperate to have a child of a particular sex, probably the most scientifically supported technique is the Shettles method, the brainchild of the late Dr Landrum B. Shettles.
The Shettles method
Shettles was an American pioneer of in-vitro-fertilisation techniques, the Roger Federer of gender selection and had a symmetrical family of three boys and three girls to prove it.
The Shettles method is based on first determining the time of ovulation and then arranging the love life accordingly.
A success rate of around 75 per cent is claimed for this method, which is not bad in a field where every Tom, Dick and Harry has his own theory.
My method for predicting the gender of a child (which has a success rate of more than 70 per cent) goes like this.
Examine the sire and place him on a scale of machoness from 1 to 10. The higher the score, the greater the likelihood of a girl and vice versa.
Ultimately, the most important thing is to keep a sense of perspective. “I get really depressed when women in their thirties come to me clamouring for a boy or a girl,” says Zita West, who runs a fertility clinic in London.
“They are at an age when they just need to get on with it, without all the nonsense. The scientific evidence supporting most of these theories is non-existent.
"There is so much stress and misery around infertility that women should just think about having healthy babies — and be grateful when they do.”
TRUTHS AND MYTHS
Boy or girl?
The gender of babies is determined by the male chromosomes.
An egg fertilised by the X-chromosome will produce a girl and that fertilised by a Y-chromosome will produce a boy.
Below are some of the numerous half-baked theories about influencing and predicting the gender:
A woman can expect a girl if:
- She carries the baby high
- She gets acne during pregnancy
- The husband puts on weight (yes, really) while she is pregnant
- She gets a craving for chocolate
- The foetal heartbeat sounds like a washing machine
A woman can expect a boy if:
- She carries the baby low
- She craves for lemon juice
- The foetal heartbeat sounds like galloping horses
