“They’re very excited to welcome a new member into their family.” That quote from their reps sounds like there is already another child in the family. You don't really say that when referring to the parents family unless there are kids. Huh. But we already know that Olivia has no children, so that would just leave Jason Sudeikis. Does Jason have any kids? Not any that he has previously acknowledged. Would this be a good time to announce he has one? Is January Jones off in a corner crying herself to sleep while she drinks straight from the bottle? Maybe the family statement is a way of slowly bringing up the fact that Jason already has a family. It could also mean that Jason and Olivia are really close to their parents.
Source:
http://www.crazydaysandnights.net/2013/10/olivia-wilde-is-pregnant-naming-baby.html