There will be no more Uchiha babies, ever. Sasuke has resigned himself to that. He is fine with the Sharingan being no one's but his own, once two of the people who have shaped his life pass on. He is not interested in a brand-new family; they would not grow into people he used to know.
He knew that, but it has taken him a while to understand. The mourning stages are a funny thing.
There will be no more Uchiha babies, ever. Itachi is the judge and jury; he does not wish to lose his objectivity with a family. As for accidents, Itachi doesn't feel desire for anyone but people he can see pieces of himself in; and competent, highly focused, highly lethal ninjas are rarely interested in carrying to term a missing-nin's child.
Even if Itachi wasn't more interested in fighting them than fucking them. Even if he didn't end up killing most of his rare bedmates anyway.
There will be no more Uchiha babies, ever. Neji isn't really equipped for that anyway; though the reason why Itachi didn't kill him has less to do with that little perk than with the way Neji tried, and almost succeeded, to kill him in the afterglow.
There will be no more Uchiha babies, ever. And it aches, but it's better for everyone. Neji watches Sasuke as Sasuke watches Hinata's child, all dark hair and pale skin and wriggly limbs and simple joy and total trust. There will be no Branch Hyuugas from Neji, ever, either.
There will be no more Uchiha babies, ever. No more squeals and no more total trust and no more innocence, no more bright futures and endless hopes. It doesn't stop Sasuke from wishing Itachi would give them back to him.
NO, Itachi didn't castrate Sasuke! XDDD seriously, you guys, what the heck? XD *dhed*