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Male Fertility Also Affected by Weight

Katlyn Joy |10, September 2014


For a long time, a man's role in the fertility issues was overlooked. Now we are beginning to understand that when a cause has been identified, it is nearly as likely to be a problem with the man as with the woman.

One such fertility factor that involves the man is his weight. Women wanting to conceive have been advised to get their weight to an optimum level for the best chances at conceiving and having a healthy pregnancy. It seems that advice should extend to the men as well.

The latest research is from a new study published in the journal Clinical Endocrinology. This study found that obesity affects sperm quality as well as concentration.

In September 2006, a study was published in the journal Epidemiology which looked at whether a man's weight may impact a couple's success with conception. Researchers at the National Institute of Environmental Health Sciences (NIEHS), one of the National Institutes of Health, looked at data collected from 1,468 farmers and their wives.

The participants answered questionnaires which detailed general health, reproductive history, and their overall health including height and weight. The researchers then divided the group into two groups: infertile and fertile. The infertile group included couples who had tried to conceive for a year or longer without becoming pregnant, while the fertile group had conceived in the past year. All women over 40 were not included in the study, and only couples who had tried to conceive in the previous four years were included.

Of the 28 percent of couples identified as infertile, the researchers adjusted for other factors affecting fertility such as smoking, drinking, age, BMI, and exposure to toxic materials such as pesticides and solvents. After factoring for these, a high BMI was still linked to higher rates of infertility. The infertility increase rose to two-fold among obese men.

"The data suggest that a 20-pound increase in men's weight may increase the chance of infertility by about 10 percent," says Markku Sallmen, lead author.

Then in March 2012, another study appeared in the journal Archives of Internal Medicine. This study concluded that overweight and obese men were more likely to have lowered sperm counts or no viable sperm compared to men of normal weight.

Sébastien Czernichow, who leads the nutrition department at Ambroise Paré University Hospital in Paris, and Jorge Chavarro, assistant professor of nutrition and epidemiology at Harvard School of Public Health, co-authored the paper, and looked at data from 14 other studies involving over 10,000 men.

The results were strong. Compared to normal weight men, overweight men were 11 percent more likely to have low sperm counts, and 39 percent more likely to have no sperm in their semen. For obese men, the numbers were higher. Obese men were 42 percent more likely to have low sperm counts, and 81 percent more likely to not have sperm at all.

These data strongly suggest that excess body weight affects sperm production," said the researchers in their report.

The findings may help explain why the global obesity epidemic has run parallel with a decrease in male fertility, said Dr. Czernichow.

In their findings, the researchers stated that more research is needed to look into how obesity affects sperm cells.

Czernichow however did offer a couple possible reasons obesity and infertility are linked. First, he suggested that fat tissue can convert testosterone into estrogen.

"More fat tissue, more estrogens," he said.

Another possibility is that the fat cells produce a hormone, leptin, which might damage sperm cells, or cells that produce sperm.

Still another suggested link is that with higher BMIs, meaning more fat, the temperature of the testicles is increased, lowering sperm counts.

What to Do

If your husband is carrying some extra pounds, include him in your quest to become physically fit prior to conceiving. Develop a nutritious diet that works for your tastes and lifestyle, so you can sustain it. Exercise together most days, even if it's just an after-dinner walk. Make sure you get plenty of quality sleep, so turn off the TV in your bedroom, and make your bedroom a relaxing oasis. Quit any bad habits, such as smoking. Should you experience difficulties with conceiving, talk to your doctor about possible factors.

Related Articles

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Walnuts May Improve Male Fertility New Study Shows

Cell Phones and Male Infertility: Another Study Finds a Link

Losing Weight Before Trying to Conceive

Medications That Can Harm Your Fertility


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