Infertility is a sensitive issue that can leave many women feeling alone in their unfulfilled dreams of getting pregnant.

What they don't know is that they are hardly alone. According to the American Society of Reproductive Medicine, infertility affects 7.3 million women and their partners in the U.S. — that's 12 percent of the reproductive-age population. And as scientists are beginning to discover, even the most seemingly insignificant things can add up to sabotage your baby-making efforts.

In fact, a new study says stress can double a woman's risk of infertility and something as simple as a 20-minute walk can help her chances. Getting pregnant is never easy (and not always sexy), so to dispel the stigma of infertility (and help you get lucky between the sheets this month), here are some other things you didn't know.

Infertility fact

1. Being Too Fit Can Hurt Fertility (Just Ask Norwegians).
In all medical matters, physical fitness is king. You can't be too overweight to conceive and you can't be too underweight to conceive. So the fitter the better, right? Well, not exactly. According to researchers at the Norwegian University Of Science And Technology, 7 percent of all Norwegian women have fertility issues. They conducted a study involving 3,000 women and found that having an exhaustive workout regimen was decreasing their fertility.

2. Uh-Oh For Having A Blood Type O.
Scientists from Yale University and the Albert Einstein College of Medicine discovered that among female fertility patients in their 30s, those with type O were twice as likely as other blood types to have a hormone profile that made their ovaries seem older than their age.

3. Your Fertility Problems Can Bring You Closer Together.
If you worry that the stress of trying to conceive will take a toll on your relationship, we have some promising research to allay your fears: Infertility problems can actually bring you closer together. Findings in Acta Obstetricia et Gynecologica Scandinavica, a journal published by Wiley on behalf of the Nordic Federation of Societies of Obstetrics and Gynecology, indicate that after 12 years of follow-up, couples who were able to overcome their fertility problems were more intimately bonded through a perception of joint hardship — a concept known as "marital benefit."

4. Stronger Bones, Weaker Ovaries?
Women are encouraged to drink milk for stronger bones, but do we sacrifice our ovaries in the process? One Harvard-affiliated study found that women who eat lots of low-fat dairy products face an 85 percent higher risk of ovulatory infertility than women who consume little or no low-fat dairy products.

5. A Lack Of Sunlight Can Affect Your Fertility.
There must be something to the summer being the "season of love" after all. Scientists at Austria's University of Graz conducted a study and found that women have been found to ovulate less and their eggs have a reduced chance of implanting in the womb — in the winter months. Vitamin D helps boost levels of the female sex hormones progesterone and estrogen by 13 percent and 21 percent respectively, regulating menstrual cycles and making conception more likely.

6. Here's A Serious Reason To Floss.
No one likes the dentist, but you'd never realize how keeping your pearly whites clean can affect your chances of getting pregnant. Periodontal (gum) disease delays a positive pregnancy test by two months or more, found an Australian study. They found that women with gum disease took an average of just over seven months to become pregnant — two months longer than the average of five months that it took women without gum disease to conceive. Swollen gums and deep pockets around the teeth breed bacteria, which enter the bloodstream and trigger inflammation — potentially reducing an embryo's chances of implantation.

7. Cut Back On The Popcorn.
Your late night snacking habit could be hurting your chances for kids in the long run. A study conducted at the University of California, Los Angeles, found that the chemicals in the bag lining accumulate in your bloodstream through the popcorn. And it's not just microwaveable popcorn — it's hiding in Teflon and other stain- and stick-resistant materials. What's even scarier is that the chemical is detectable in the blood of 95 percent of Americans. So pop your own kernels!

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