I dunno, I always thought that the Voyager writers were kinda lame for pushing the proverbial reset button even with the baby. Can't have a lasting plot effect with long term consequences after all. I almost wonder if the Doctor just told Seska that to screw with her head as a little payback.
I do wonder if Culluh would have bothered raising the child. Sure he took it with him, but I could easily see him growing angry at it as a reminder of his defeat and loss and end up sending it to those slave mines. Though yes, it's equally possible that Jal Cardassian grows up to amount to something.
Having another kid with Naomi might be interesting, but then again I guess pulling the quick growing up trick with two children would be a bit redundant. Besides, Voyager's future track record with certain Borg babies being known, the kid could be better off with Culluh.