Consumption of residues of steroids in meat/beef by pregnant women may be lowering fertility in their sons. - Study published in the journal Human Rep

Eating beef could threaten sons' fertility - Telegraph

Extracts:

"Prof Shanna Swan, lead author of the study published in the journal Human Reproduction, said: “These findings suggest that maternal beef consumption is associated with lower sperm concentration and possible sub-fertility, associations that may be related to the presence of anabolic steroids and other xenobiotics (foreign chemicals) in beef.

“Theoretically, the foetus and young children are particularly sensitive to exposure to sex steroids. Therefore, the consumption of residues of steroids in meat by pregnant women and young children is of particular concern.”

But while the study results revealed a significant link between the lowest sperm counts and mothers who were the highest beef consumers, researchers could not pinpoint hormones, pesticides or other environmental chemicals as a direct cause.

“What we’re really doing here is raising an issue,” said Prof Swan, who is director of the Centre for Reproductive Epidemiology at the University of Rochester, New York.

“The average sperm concentration of the men in our study went down as their mothers’ beef intake went up.” "

"Dr Allan Pacey at The University of Sheffield, said: “That hormones given to cattle might have lowered the sperm counts of adult men because their mothers ate a lot of beef when they were pregnant with them, is alarming to say the least. This clearly needs to be investigated further.” "

You really do need to read the whole article because there are conflicting views.