The wedding dress Donna wears in this episode is the same dress she wore in The Runaway Bride (2006).
According to Steven Moffat, the squareness gun is the sonic blaster used by Jack Harkness in season 1. After Jack leaves it in the TARDIS, River Song will take the gun in The Doctor's future.
Donna's children, Joshua and Ella, were named after Steven Moffat's son Joshua and his best friend Ella. The accompanying Doctor Who Confidential (2005) episode shows Moffat visiting the set with Joshua and Ella to watch part of the episode being filmed.
The phrase, "Time can be rewritten", is first uttered by The Doctor in this story and is a recurring phrase throughout Series 5 and 6.
Working titles for this episode included The Doctor Runs, Forest Of The Night, River's Run and Return Of The Dead.