Her second tip: Pregnant women who fear for their future fetus' fertility should avoid heavily using plastic products known to contain phthalates -- softening agents that are suspected to have an effect on sperm count.
"There's also the question of water," she added. "Using reverse osmosis, charcoal filtered or distilled water is probably a good thing, and again there's no harm in doing this."
And then there are the no-brainers.
"Of course, by the way, smoking is not good for sperm count," she said. "Neither is excess alcohol, though I don't think men who are trying to conceive are going to go out and get blasted every night."
But while adherence to these tips may solve part of the problem, researchers say the true solution to safeguarding men's sperm counts lies in finding and eliminating hidden culprits in the environment.
"Most of these products are silent -- they are introduced to our environment without us knowing, and we have no control over it. So it is very hard to avoid them," Swan said.
"I'm hoping we can reverse this trend."