Alan Ball - the HBO drama's departing showrunner - told TV Guide that the next season will run shorter than the usual 12 episodes.
The reduction is linked to star Anna Paquin (Sookie), who is currently pregnant and is expected to give birth to twins in November.
"We're moving production to January to accommodate her," Ball announced. "And there will only be 10 shows next season partly because of Anna and partly because of the economics."
True Blood was renewed by HBO back in July, alongside Aaron Sorkin series The Newsroom. Season five will air in the UK on FX from Monday, September 17 at 10pm.