GMOs is only one of many things that can cause reproduction or fertility problems:
Alkylphenols, Bisphenol A, Organochlorine Pesticides (OCs), Phthalates, Polyaromatic hydrocarbons (PAHs), Polybrominated diphenyl ethers (PBDEs)
http://www.ewg.org/sites/humantoxome/
Great point, @lugh. There are many things in our environment and food supply that are creating the fertility epidemic. Thanks for sharing this link