Britney Spears drew a crowd of 3.7 million viewers who tuned in to watch her TV documentary on Sunday.

The pop star talked about the series of public meltdowns that led to her two hospitalisations earlier this year in MTV special Britney: For the Record.

Spears welled up with tears during the 70 minute interview, as she spoke about losing custody of sons Sean Preston, three, and two-year-old Jayden James, and her failed marriage to former dancer Kevin Federline.

The show's ratings surpassed nearly every major show with the exception of the annual Video Music Awards, according to network bosses.