What's the Link Between Obesity and Infertility?

For couples struggling with fertility, there’s an unlikely tool that could help—the scale.

That’s right. Being overweight or obese can affect a couple’s ability to get pregnant.

In fact, obesity is the cause of fertility struggles in six percent of women who have never been pregnant before, says the American Society for Reproductive Medicine (ASRM).

Obesity affects infertility by changing the way a woman’s body stores sex hormones. Here’s how:

1. Fat cells convert a male hormone known as androstenedione into a female hormone called estrone.
2. Estrone affects the metabolism of the part of the brain that regulates ovarian and testicular function.
3. This can impair reproductive function.

And it’s not just the woman’s weight that affects fertility. Obese men are more likely to have low or nonexistent sperm counts, according to a March 2012 article in JAMA Internal Medicine.

This happens for several reasons:

1. Obesity can elevate body temperatures, especially around the scrotum.
2. It can also lead to hormonal imbalances. Obese men are more likely to have higher estrogen levels, combined with lower levels of sperm-producing hormones like inhibin b and androgen.
3. This can mess with sperm count, sperm concentration and the sperm’s ability to swim well, according to a March 2010 study in the journal Nature Reviews Urology.

Making Fertility Issues Worse

besity and infertility can have a weird, circular relationship as well. It’s hard to tell which one caused the other. For example, stress—like the kind couples experience during a long fertility journey—can not only cause irregular periods, but some women “stress eat,” meaning they binge on junk food during times of stress.

Then, there are health conditions like polycystic ovarian syndrome (PCOS), a hormonal disorder that can cause cysts on the ovaries. While the cause of PCOS is unknown, one side effect of PCOS is obesity. The National Infertility Association points out that obesity is common among PCOS patients, affecting 50 to 60 percent of women with this condition. The symptoms may be worse if a woman is obese.

Take Charge of Your Health

Sometimes addressing fertility challenges starts with getting to a healthy weight. Losing weight is a simple concept, but in practice, it’s not always easy. If changing your diet and exercising have not worked, you may want to talk to your doctor about bariatric surgery. It may be worth considering if you:

• Are more than 100 pounds above your ideal weight
• Have weight-related health issues, like high blood pressure or Type 2 diabetes
• Have tried weight loss programs, but nothing has worked
• Don’t have any current challenges with alcohol or drug abuse

Think about it. If obesity is the underlying cause of your fertility challenges, it’s best to address that before starting or continuing fertility treatments. Talk to your doctor about how your body weight may be affecting your fertility.