Sally McMillan has given birth (as had Susan Saint James in real life). But the only reference to the baby comes early on, when Mac's mother asks him how the baby is doing. Mac pauses noticeably and says, "He... is doing fine." The baby is not mentioned at all during any subsequent episodes; scriptwriters described "him" as a script encumbrance mentioned only because of Susan Saint James' real-life pregnancy. (She is also pregnant at the end of the first season, and one episode begins with her being rushed to the hospital to check on complications.)
Randy Murphy says he works for "Central Security" (the word Agency wasn't used). For some reason in the mid 1970's, NBC or Universal did not want to use the real names of governmental agencies. It was common for the CIA to be called something like the National Intelligence Agency, or as in this case, just Central Security.
When Mac goes to see Luther Dorfman(Richard Deacon), there are several signs backstage reading Bradley Merrick. That was the name of a character from the last Banacek episode; also featuring Gretchen Corbett.