A woman has a drunken one-night-stand and ends up pregnant. She and the father then attempt to cope with the situation and determine if they have any feelings for each other.
Judd Apatow's last film (The 40-Year-Old Virgin) belabored its central relationship. Knocked Up errs in the opposite direction. In the midst of some appealing true-to-life moments, surprisingly little effort is invested in making the relationships believable. We never see Alison and Ben falling in love, or Debbie and Pete fix their marriage, and yet we're supposed to believe these things occurred.
The movie works better as a comedy. In particular, Jason Segel and Kristen Wiig provide brief, welcome shots of skewed hilarity.