Have a burger and chips before getting pregnant and you're more likely to have a baby boy whereas a girl is more likely if you eat chocolate or ice cream. It may sound about as convincing as puppy-dogs' tails, but this is the latest cutting-edge science as reported in the New Scientist.
It is said that there is a global trend that more girls are being born than boys and the number of girls are increasing. It's a fractional increase. But all the evidence suggests that the underlying trend is an increase in physiological stress in women that causes the low blood sugar levels that is being reported in the New Scientist.
A major cause of this stress appears to be pollution, particularly from the chemical dioxin. One of the biggest leaks of the chemical, from a factory in the Italian town of Seveso in 1976, had a dramatic impact on the sex ratio of babies born in the area: in the seven years after the accident, births totalled 46 girls and only 28 boys. A similar impact was reported in October 2007 from airborne dioxins: a Canadian study published in the journal of the American Chemical Society found that the sex ratio of newborns was 54 females to 46 males in a 25-mile radius of sources of dioxin pollution compared with the normal 51 boys born for every 48 girls.
As well as pollution, the weight of the mother may also play a part. Women's weight is increasing at the same time as the ratio of female babies. Women with an above average body mass index (BMI) are more prone to gestational diabetes and have lower blood sugar levels and this seems to explain why they have a higher chance of having a girl baby. It could even explain why some researchers claim that single mothers are more likely to have girls, as they may be subject to more physiological stress.
Thousands of couples are yearning for a baby of a particular sex, but can you really influence it? Here are some theories:
* Coffee: If a man has a coffee before sex, the Y-sperm is more active and likely to result in a boy.
* Age: As a mother gets older, her chance of conceiving a boy increases.
* Dreams: Whatever sex of child a mother dreams of having, she will have the opposite.
claim = tvrdit
conceive = otěhotnět
convince puppy-dogs' tails = doslova přesvědčovat “oháňku štěněte”, aby poslouchala, uvěřit něčemu
cutting-edge = nezkreslený
desperate = zoufale potřebující, zoufalý, zuřivý, náruživý
gestational diabetes = těhotenská cukrovka
hanker after = bažit, toužit, lačnět po
impact = dopad
leak = únik, prosakování
long for = toužit, dychtit po něčem
prone to = náchylný, mající sklon k
underlying = zásadní
whereas = zatímco, kdežto
yearn for = prahnout, toužit po
Zdroj: the New Scientist 2007, the American Chemical Society, výzkumy Jane Feinmann, Roger Dobson, Richard Sharpe
