When I saw "Knocked Up" in the theater, scene that elicited the greatest collective audience reaction happened when the bambino implied in the title is about to arrive into the world. If you've seen it, you know what I'm talking about. The infamous crowning shot, which made childless couples everywhere realize that the delivery room can be a scary place.
If Judd Apatow had decided to film a period comedy set in 1938, that scene might not have made the final cut since Seth Rogan and his cronies wouldn't be anywhere near the laboring Katherine Heigl.
At that time, barely half of American births were even happening in hospitals, and they were largely all-female affairs. Judith Walzer Leavitt, author of Make Room for Daddy: The Journey from the Waiting Room to the Birthing Room summarizes that male migration to the birthing bedside:
After the 1980s, delivery room duty became a social requirement for expectant fathers. Tim Blackshaw estimates that the percentage of dads in the delivery surged from 5 percent in the 1950s to 97 percent in the 1990s. "The absentee father is now a rarity - a 'statistical deviant'. In the present consumer-orientated
health service, healthcare professionals would want to be certain that they
could justify the exclusion of a father from the birth of his child."
Personally, I don't think there should be so much pressure on expectant fathers. Once I learned that some attendant dads experience PTSD-like symptoms and lost any sexual desire for their wives-turned-new-mothers, I decided I might encourage my hunk in question to kick back and hang out in the waiting room and come back when I'm dewy and glowing -- or as close as you can get to that post-birthing. Or maybe lamaze classes should just start screening that scene in "Knocked Up" as a type of final exam to ensure that the dads know what they're signing up for.