TBH,I dont think that is possible.A kakuja is manifested by a large abnormal growth of RC cells.It's a mutation so to speak,like cancer,but it doesnt kill you.To have your baby become a kakuja,they somehow have to inherit that many RC cells,which could lead to complications. Best-case scenario:complications during pregnancy or birth.
Worst-case scenario:rips out of mama's stomach and comes roaring into the world like a kamikaze baby,which would be SUPER COOL!
Well think about it. A fetus consumes what its mother eats, therefore as its mother is cannibalizing it is too. So that would probably where it would get the huge amount of Rc cells. Idk, this is just one of my crazy theories.