No but Bilbo coming home an realizing he’s pregnant. Thorin just died and he can’t deal so he gives the baby to a young couple that can’t conceive. Not even Gandalf knows. Then Primula and Drogo die, and Bilbo can’t help but take Frodo in, naming him the heir of Bag End that he actually is by blood. Frodo never knows, until on the boat to the Undying Lands Bilbo tells him. The troubles that he was having with the ring is actually caused by some pesky Durin genes of madness and greed. That he is the actual heir of an ancient dwarven kingdom. And everything just clicks for Frodo, because neither of his parents had ice blue eyes and his hair is both darker and thicker than his fathers. The unusual sharpness of his face, the aura of nobility he gives off and leaner frame. It all makes sense.
And in the background Gandalf is truly shocked. Because he didn’t know male hobbits could give birth and thought Frodos strangeness to merely be a product of early tragedy, some extra Took and growing up with Bilbo, no matter how similar to Thorin he looked and acted. Because he didn’t ever meet Prim or Drogo. He never knew them. And also Gandalf being both amazed, annoyed (and a bit hurt) that Bilbo never told him so he says something about the stubbornness of hobbits and dwarves and how this jeopardized the quest and that he “should have known when Frodo didn’t even look weak in his knees once”. So Bilbo mutters something about “not prepared” and “dragons are rather dangerous”.