It's one of many reasons why I prefer my own headcanon where Mariel makes a lot of money writing a trashy tell-all instead.:)

(A serious Mariel rant will come at the section in question.)

Clearly, Delenn's hybrid physiology strikes again, in David's universe, with the two years of pregnancy. I'm assuming everyone else (except for Vir) took two years in order to get their new jobs as well. It's just such a nonsensical canon change that it makes my head ache every time I think about it.