With the exception of Paul Rudd, the actors who play Ben's friends all keep their real first names for their character's names.
Originally to be a follow-up to 40 anni vergine (2005), having Seth Rogen and company reprise their roles as the Smart Tech team.
The kids who play Debbie and Pete's children are the real-life children of Leslie Mann and her husband, director Judd Apatow.
Judd Apatow has stated on the DVD commentary numerous times that the film is partially based on the birth of his and Leslie Mann's first daughter, Maude. Scenes taken directly from reality include Ben trying to get their doctor on the phone, and cussing out numerous doctors when he can't; the cantankerous staff physician whom Ben has to take out into the hallway to calm down; the argument on the way to the clinic, where Allison throws Ben out of the car; and then they argue at the clinic when he gets there; and the scene where Allison tries to take a bath to calm herself, just before going to the hospital.
Stormy Daniels: a lap dancer. In April 2018, during an interview on Ellen: The Ellen DeGeneres Show (2003), Seth Rogen said that while she was on the set of this movie, Daniels told him and others about her then-recent affair with Donald Trump. When the story of the affair emerged after Trump was elected US president, Rogen recalled that he'd heard Daniels's account of it a decade earlier. It was Trump's interactions with Daniels that led to him becoming, in March 2023, the first US president (current or former) ever to be indicted for a crime.