A "CAT"astrophe in fertility?

I've noticed something while trolling around the infertility blogosphere - an awful lot of infertiles have cats, and I am the proud mama of two fantastic felines, too. So, I'm wondering if there is a direct correlation between owning cats and being baby-making challenged. I think this warrants some research by the NIH or at least the Humane Society or an investigative report by Cat Fancy.

A couple of theories here, mind you, I am not a scientist or a psychologist, but indulge me a bit:
1. My cats are so happy being "only" children that they have some kind of curse on my uterus that renders me infertile.
2. There is something in cat dander, pee or poo that escapes into the air that deems some people infertile.
3. Infertiles who want children have a lot of love to give, so they have furbabies to parent, spoil and adore, until the human version arrives.
4. They're so upset by being spayed, that they curse your uterus so that you can't have babies, either.
5. The hours of cats sitting on my lap and making biscuits on my stomach over the years has smashed my uterus into an inhabitable place for a embryo to grow.

I'm pretty sure that the answer is #3, but I think it's still worth some research. I will happily sign up to be studied.

Any other theories?