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The New Surprising Way To Predict The Future Sex of Your Children

You don't have to wait for a sonogram to know whether you figure out if you should be coming up with boy names or girl names. In fact, you don't even have to be pregnant.

That's because Japanese researchers just discovered an interesting factor that plays a big part in the likely sex of a woman's baby. (Sidenote: We would still highly suggest you wait till you're expecting before discussing baby names with your boyfriend. Two words: boner shrinker.)

But if you're curious, here's the deal: The earlier you got your first period, the greater the chances are that you'll have a girl. Scientists in Japan studied 10,000 mothers and learned that women who started menstruating at 10 are more likely to have girls (54 percent of this group of moms gave birth to females). The women who didn't get their period till 12 had a 50/50 chance. But those who were 14 when their period started had a higher chance of giving birth to a boy (53 percent versus of the time).

Related: 8 Moves That Keep Your Body Baby-Ready

Sure, the difference in percentages seems tiny and clearly it's not a surefire way of knowing what you'll have (considering plenty of women have babies of different sexes), but the study is still interesting.

(And for all of you biology experts who are wondering how this is possible since it's the sperm that determines the sex of a fetus, the researcher pointed to research that found "higher levels of the female sex hormone oestradiol in women who entered menarche before the age of 12 [which] may lead to spontaneous miscarriage of fertilized male eggs," according to an article on newscientist.com.)

What do you think of the connection between when a woman gets her period and the sex of her baby? When you get pregnant, will you want to know the if it's a boy or a girl? Or do you plan to wait and have it be a surprise?

Read more at Cosmopolitan.com!

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