Burnett approached the charity with the offer of producing the ad on a pro bono basis. The 60-second film will run in cinemas during the FPA's Sexual Health Week from 4 to 10 August.
The film, entitled "hand signals", features the Holby City actress Lisa Faulkner. As part of a game, Faulkner gets couples in the audience to hold hands.
First, she urges the viewers to squeeze their partner's hand if they fancy them, if they like sex and if they are thinking about sex at that moment.
She then asks them to squeeze their partner's hand if they've ever had sex with anyone without using a condom, before revealing that by doing so, they've put themselves at risk of contracting chlamydia, which can cause infertility. The commercial ends by giving the FPA's helpline number.
The ad is aimed at couples aged between 16 and 24. Cinema was chosen because of its ability to secure this demographic as a captive audience.
Sonja Webb, the communications director at Leo Burnett, said: "We developed the script and approached the Family Planning Association because of its high-profile campaigning work on sexual health. We felt passionately that the ad should be made and our partners all gave very generously of their time."
Karen Brewer, the FPA's director of communications, said: "We were delighted to be contacted by Leo Burnett. This is the first time we've tried cinema advertising, and it's an exciting step for the FPA."
The film was written and art directed by Angus Macadam and Paul Jordan and directed by Patrick Bergh through Partizan. Media planning and buying is by PHD.