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December 11: International baby-making day?

International Baby Making Day?On average, more children are conceived on Dec. 11.

Got a sexy date with your significant other tonight? On average, more children are conceived on Dec. 11 than on any other day of the year. You have been warned.

According to new research, Sept. 16 is the most popular birthday in the U.K. With the average gestation period for a baby being 40 weeks, December 11th has been dubbed the most fertile day of the year.

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In 2006, the New York Times published a table of how many American babies were born on each day of the year between 1973 and 1999. September 16 also came out on top.

Check out an infographic of the results here.

Not only is Sept. 16 the most popular birth date, September in general is the most popular birth month in the U.K. and United States, making December the most popular month for conception.

Amitabh Chandra, professor of public policy at Harvard University, who conducted the research on American birthdays, says that it wouldn't be a stretch to assume some similarities between Canadian conceptions and births and his south-of-the-border findings.

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"I guess the old saying is, what else is there to do during the winter anyway? And now we know," Chandra tells the Toronto Star.

"It would be interesting to see the difference in cold weather areas like Canada and cities in the south to see if more babies are produced in the winter," Chandra adds.

Why the baby-making boom at the end of the year? Scientists have two explanations, the Daily Mail reports:

Sperm quality is higher in the cold and with festive events and holiday cheer, people are having more sex.

Being snowed in can't hurt conception odds either.

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Also interesting, condom sales typically spike the week before Christmas. So while it may be baby-making season, it's also intentionally-not-making-a-baby season.

Do you have a September baby?

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