Neglected basis for Rhaegar's supposed annulment: fraud

There's been a lot of discussion that any supposed annulment of Rhaegar and Elia's marriage would be legally impossible because the marriage was obviously consummated, resulting in two children. Some dispute this on the facts: one theory I've seen is that Arthur Dayne is the father of Elia's children.

There's also the debate over whether Aerys forced Rhaegar to marry, which could have supported annulment for lack of consent. However, consummating the marriage would probably cure this problem (unless Elia forced Rhaegar to have sex with her—twice).

But even assuming the marriage was consummated and force wasn't/isn't an issue, fraud remains a possibility. If Rhaegar was married under false pretenses and didn't discover the fraud until after Elia's children were born, that can legally support an annulment. False pretenses might include that Elia was previously married, was still married, was not a virgin as claimed, and so on.