The box under the TARDIS console the Doctor opens has the words: "TARDIS. Time And Relative Dimension In Space. Build Site: Gallifrey Blackhole Shipyard. Type 40. Build date: 1963. Authorised for use by qualified Time Lords only by the Shadow Proclamation. Misuse or theft of any TARDIS will result in extreme penalties and permanent exile." written on it. This is also written on a plaque on the console itself, as shown in the TARDIS tour on the BBC website.
Karen Gillan had to wear a latex prosthetic stomach bump for the scenes which depicted Amy as pregnant. She claimed it made her feel more mature and act ridiculously, and cited it as her favourite part of filming the series.
This is the first story of Series 5 not to have any cracks, silence or direct foreshadowing of the finale.
The old age home in the episode has a big sign reading "Sarn", which is also the name of a planet visited by the Fifth Doctor in "Planet of Fire".
In the dreams, the Doctor wears both variations of his outfit. He wears the teal version in Upper Leadworth and his maroon version in the TARDIS.