1) Need a Redeemer? (Which begs the question why since they're innocent?)
or
2) Don't need a Redeemer? (Christ didn't die for all)
If I understand correctly, the idea is that they are redeemed in the womb or sometime prior to their unfortunate early demise. They are not "innocent" on their own merits, but are made that way through a special grace of God.
SD
Then one would have to conclude with OP that if they are not innocent on their own merit they must be sinners from birth.