Sperm determines the sex of the baby

So it all comes down to the banana. The yellow fruit with the phallic shape — appropriate in this context — is the best dietary aid for intending mothers wanting a boy, according to research published yesterday. In what they claim is the first scientific evidence that diet influences infant gender, researchers at the Universities of Exeter and Oxford have found that women who consume more calories around the time of conception, and, in particular, eat more bananas, are more likely to have sons. At the same time, those who skip breakfast and breakfast seems to be key are more likely to have daughters. The differences are extremely slight. In the study, 56 per cent of women with a high-calorie intake had boys compared with 45 per cent with a low calorie intake.

Despite most parents ultimately just wishing for a healthy baby, there are many cultural and social factors that can drive the desire for a baby of a particular sex. The medical technology for sex selection of embryos has existed in Australia for many years, but such an option is only available for medical reasons, such as sex-linked chromosomal disorder. This leaves parents who do have a gender preference looking for natural ways of predetermining the sex of their baby. In the s, the idea that timing sex around ovulation can tip the odds in favour of a girl or a boy was popularised by Shettles and Rorvik in the best-selling book How to Choose the Sex of Your Baby.

More about how the environment can affect sex ratios of children. The chances for a boy or a girl are a lot like the chances of getting heads. A female bluestreak cleaner wrasse can turn into a male when necessary.

A Newcastle University study involving thousands of families is helping prospective parents work out whether they are likely to have sons or daughters. The work by Corry Gellatly, a research scientist at the university, has shown that men inherit a tendency to have more sons or more daughters from their parents. This means that a man with many brothers is more likely to have sons, while a man with many sisters is more likely to have daughters. The research involved a study of family trees containing information on , people from North America and Europe going back to We now know that men are more likely to have sons if they have more brothers but are more likely to have daughters if they have more sisters.