Channel 4's new comedy format King Of... is to be cut down to just four episodes as doctors have ordered heavily pregnant host Claudia Winkleman to rest.

King Of..., a new comedy show in which guests debate with Claudia Winkleman to find 'the definitive, the top, the crème de la crème - in short, the king of just about everything' was due to run for six weeks, but will now be made up of just four episodes. The show started broadcasting on Channel 4 last week with Episodes 5 and 6 still to film; however, following medical advice, the host is now unable to complete these last two recordings.

A studio recording earlier this week was cancelled. The presenter said on Twitter: "I can't do the others as am on bedrest. Was supposed to be with Ruby Wax and Jonny Vegas today. Livid..."

A Channel 4 spokesperson confirmed to British Comedy Guide: "Following medical advice, Claudia Winkleman is unable to continue with any work commitments. As Claudia is essentially the king of King Of... it will mean that the last two episodes will not be filmed. We are delighted with the episodes we have and look forward to working with Claudia soon."

The first episode, which was broadcast last week, saw Winkleman - clearly heavily pregnant - chased around the studio by a penguin (pictured).

The three other episodes that have already been recorded will be shown, as planned, as part of Channel 4's new Friday night comedy line-up, sandwiched between 8 Out Of 10 Cats and Chatty Man. Tonight's episode, which will be shown at 9:30pm, involves guests Jessie Wallace and Stephen Mangan, whilst the guests on the other episodes already filmed are Lorraine Kelly, Jack Whitehall, Miranda Hart and Micky Flanagan.

Winkleman's pregnancy has also caused complications for Radio 2 panel show Hot Gossip. Winkleman has hosted the previous 3 series of the show, but DJ Sara Cox will take over hosting duties when Series 4 begins tomorrow.