The Thelma & Louise actress, who suffers from uterine condition endometriosis, made the surprising admission during a special chat with Scottish actor Alan Cumming as part of his new Lucid Conversations private sessions, which was held in New York on Monday (06Feb12).
Sarandon was describing the difficulties she had experienced trying to fall pregnant when she came clean about her romp with Italian director Franco Amurri back in the 1980s.
She told the audience, "It (endometriosis) grows like a vine. It can do all kinds of horrible things. But, you know, the kind of guys that I was seeing weren't really very good candidates for father at that time. So I wasn't looking to have kids really. And then...
"If anyone out there's having trouble getting pregnant. Go to Italy. Have a summer and don't worry about it and eat and drink and... f**k, and you'll probably get pregnant. And that's what happened with Eva. On the Spanish Steps."
Sarandon's confession shocked Cumming, who replied, "Seriously? On the Spanish steps? That's where Eva was conceived, on the Spanish steps?", before raising his glass and toasting the actress, saying, "Cheers to that!"