Even though she has admitted she hates them, it was Eve Myles' idea for Gwen to eat a bunch of gherkins, relating to the old cliché that pregnant women always crave pickles.
The stables where this was filmed, Tredegar House, was also used in The Next Doctor (2008) and The End of Time: Part One (2009)/The End of Time: Part Two (2010).
This episode was specifically designed to be more comical than the others in the season.
The original title was "The Wedding".
William Thomas, who plays Gwen's father Geraint, is the only actor to have appeared in both Torchwood and the Classic and New eras of Doctor Who. He featured in Remembrance Of the Daleks with Sylvester McCoy, and Boom Town with Christopher Eccleston.