Obesity can cause fertility problems in men

According to new research obese men have lower volumes of seminal fluid and a higher proportion of abnormal sperm.

The scientists say obese men if they want to have children, should consider losing weight.

Dr. A Ghiyath Shayeb, from the University of Aberdeen, in Scotland and his colleagues examined the results of an analysis of seminal fluid in 5,316 men attending the Aberdeen Fertility Centre with their partners because of difficulties in conceiving.

Of the men, complete data on 2,037 regarding their BMIs was available and the researchers were curious as to whether male overweight might contribute to fertility problems, as it is a known risk factor for women trying to conceive.

The men were divided into four groups according to their BMI, from being underweight through to being considerably overweight.

The researchers found that even after other characteristics were accounted for such as smoking, alcohol intake, age, social deprivation and the length of time of abstinence from sex prior to producing a semen sample for analysis, men who had a BMI of 20-25, considered to be an optimal BMI, had higher levels of normal sperm and also had higher semen volume.

The researchers say their findings suggest that men who are trying for a baby with their partners, should first try to achieve an ideal body weight.

They say other research has also suggested an association between male obesity and increased DNA damage in the sperm and they advise obese men to adopt a healthy lifestyle, with a balanced diet, and regular exercise which will they say, in the vast majority of cases, lead to a normal BMI.

The team intends to follow up their research by comparing male BMI in fertile and infertile couples to see if the poorer semen quality correlates with reduced fertility.

Dr. Shayeb says further research is also needed on exactly how obesity affects semen production.

Dr. Shayeb presented his research this week at a conference of the European Society of Human Reproduction and Embryology.