As a student doctor I find myself diagnosing all the time when I'm watching tv 😆, so I've been wanting to clear this up for a while. He's unlikely to be impotent (he probably would have noticed!) but as the doctors say he can '
never' (a word we're told never to use - that and 'always'!)
be a father, taking their words literally (provided I was paying attention of course) it probably means that the samples [they must have taken samples, you can't test fertility with just a blood test] show there's no viable sperm = no baby. Obviously these aren't real doctors (doesn't mean I can't analyse bad practice - I just do it in my head instead of out load and annoying everyone) so Krishna may still be able to have children depending on what miracle decides to occur.
I'll stop rambling on. Sorry for being boring/confusing/uselessly incomprehensible with my dialogue. I would attempt to diagnose K's problem, but I don't have full history - and in these histories things get very detailed. I should go and revise this topic rather than sitting on IF...