Yeah you can definitely sell anything to a couple who is trying to get pregnant, especially if you know they've been trying for a few months without success.
I've read some peer reviewed research as well but most of that is focused on outcomes and genetic testing of IVF embryos rather than natural fertilization. I get the impression that fertility isn't something that's well-studied outside of really generic health indicators like weight and age. And a lot of fertility information seems to focus on ages 20 to 35. They seem to assume that after that age you've given up on starting a family or that you already have one.