In Dragon Ball Z what episode is trunks born?

Answer 1

I think that the episode trunks show when he was a baby was episode 150 - 170.

they first show trunks with sword and new born baby trunks in the episode when goku finally returns from the planet namek :)

Answer 2

As a baby, Trunks first appears in Dragon Ball Z episode 111, when Goku and the gang are waiting for the arrival of the Androids. Bulma is holding young Trunks, while Krillan and Gohan look in shock. (They thought Yamcha was the dad, but it's actually Vegeta.) Yamcha tells them that he's not the dad and to guess who it really was. Goku goes up to Trunks and says, "I bet it's Vegeta, huh? Right, Trunks?" Bulma stares at Goku and asks him how he knew it was Vegeta, and how he knew Trunk's name. Goku starts stuttering and that's when Piccolo appears. ( Earlier, after Goku came back to Earth from being in space for 1 year and a half, future Trunks tells Goku all of this before and tells Goku not to tell Bulma or Vegeta, or they may not have married and had Trunks.)

Yeah, I know. More information than you needed, but there you go. Episode 111 of Dragon Ball Z.