The 2010 World Cup in South Africa triggered an increase in the number of baby boys born in the country nine months after the event, a study says.
The ratio of boys to girls born in that period was the highest recorded between 2003 and 2014, the study in the Early Human Development journal found.
People were more relaxed and probably had more sex during the World Cup, increasing the ratio, say researchers.
South Africa hosted their first World Cup between 11 June and 11 July 2010.
It has been known that if people have sexual intercourse more frequently there is a tendency to have more boys born than females.
The study showed the ratio of boys born nine months after the tournament was 0.5063, compared with an average during the period from 2003-2012 of 0.5029, which represented about 1,088 extra boys.
They added it was "unlikely to be due to chance or a seasonal effect."
The medical reasons for the altered sex ratio could be because of unimpaired sperm mobility, increased frequency of sexual intercourse and, or, decreased male foetal loss during pregnancy, the report's authors concluded.
So if you want a baby boy, you now know what to do....lol.