http://www.supershadow.com/starwars/episode3/spoilers.html
scroll down to the padme' rumors
finti i have to aggree with you because the time between 3 and 4 would be right and if we do see the twin i think it my be almost at the end of episode 3 i would think that if the twins weren't born on three that there would be a big gap in 3 and 4 and it would explain how they were hiddin from anakin i think i could be wrong but for me it would be a disappointment not to see the twins born in episode 3