Presuming that this is a serious query, I cannot imagine that this can be a ground for divorce, especially if you can bear children. The medical details are really irrelevant. It is inconceivable for any legal Act to cover each and every medical condition separately therefore your concern that someone may have faced precisely the same medical condition is not relevant. I fully agree with the advice rendered by advocates here that this medical condition cannot be grounds for divorce.
That said, you cannot stop anyone from filing any petition, however frivolous. His divorce petition will need to fall under some legal section such as fraud (to void the marriage), cruelty/desertion/adultery to seek divorce, etc. I do not see any of these legal remedies available to him. Therefore, you will be able to rebut his claims, head-on.
Unfortunately, the above is only legal advice. Extending myself beyond this realm, I am compelled to ask myself the question: Why is he REALLY seeking divorce? All things been normal, from a physical relationship perspective, there must be some other peripheral reason and you need to confront that specific reason. I think that there is more to this than meets the eye. Perhaps he has someone else in his life or you have an acrimonious relationship with him that he is compelled to find an excuse to get you out of his life. You need to step back and analyse the possibilities. You may be trying to find an answer to the wrong question.