Women who are stressed while trying to conceive are more likely to have girls, suggests a study by researchers from Oxford University.
The research showed that future mums-to-be facing pressure at home, at work or in their relationships in the months before pregnancy were as much as 75% less likely to have a boy.
Some 340 women from around the UK who were trying for a baby kept lifestyle and relationship diaries and filled in stress-level questionnaires while their cortisol levels were measured.
Of the babies born, 58 were boys and 72 were girls, and among the 50% with the highest cortisol levels, the sex ratio was clearly skewed towards girls.
Normally In Britain 105 boys are born for every 100 girls.
Previous studies have shown that the number of baby boys falls after massive upheavals such as the terrorist attacks of 9/11 and the economic chaos following the fall of the Berlin Wall.
This means that the current economic downturn could cause similar trends in the UK.
It is possible that high levels of the stress hormone cortisol weaken male embryos, making miscarriage more likely or making it more difficult for them to implant in the womb.
The findings will be confirmed on a larger scale after which, mothers could be told about the benefits of relaxation to cut the time it takes to conceive.