The Jagiellonian males seemed to have had a poor showing as far as fertility was concerned, with Sigismund II being the best known example. However, if one looks at other royal males of his family, with exception of Sigismund's father and paternal grandfather producing heirs seems to have been a problem.
Limiting it to those who actually married (sorry Wladyslaw III and Jan I of Poland):
Wladyslaw II had four children over the course of his four marriages of which only one left further issue.
Kasimierz IV is the only Jagiellon royal male (besides his dad) have more than one surviving son.
Wladyslaw VII was married three times and only got lucky third time around, and Ludwik/Lajos II was hardly anyone's idea of a healthy male heir at birth (premature and puny), yet Wlad never remarried after his third wife's death. Nor did he leave any bastards.
Alexander of Poland had only two miscarried/stilllborn children. Again no bastards.
Sigismund I the Old married twice and had a few kids (bastards included), but he had poor luck siring boys and so Sigismund II Augustus was the last Jagiellon king of Poland.
Sigismund II was married three times, and his only claim to paternity was a pregnancy by his third wife (ICR if this was only a rumor or if she was actually pregnant, but the child miscarried or was born dead). Even his bastard daughter's paternity is questioned.
All this leads me to believe that unless their wives were ALL bad matches genetically (how is this possible if they come from lineages as different as Hohenzollern, Foix, Habsburg and Trastamara?) these guys had a problem in their pants. The girls in the family seem to have bucked this trend, Anna of Hungary, wife of Emperor Ferdinand popped out a football team, and several of Sigismund I's daughters were well past their first youth, but still managed kids.
So, my actual question is this, even if Ludvik/Lajos II survived Mohacs, would that necessarily mean that he and his Austrian wife are assured of kids? Or put another way, at least one or two sons? Or is the Hungarian line of Jagiellons just as doomed as the Polish line?