Are there any unborn characters?

Charmed did something similiar, in one episode where the characters went in the future, to learn about something then changed their actions when they returned to the present. In the future version the character of Piper meet her daughter, later in the series she had two sons. In the story line for Stargate Atlantis, they showed where one of the chracter's came from an alternate reality. That character Rodney, had a sister, the alternate reality Rodney had 3 nieces, while the one in the reality of the series as it normally was airing had only one niece. Shows have done this for a long time it creates an interesting premise how one action, choice can change fate, or outcome of our lives sometimes it is the little things that we do not even pay attention to that may be making the changes and sometimes it is the big things or big choices.