Media
Kaplinsky, who joined Five from BBC One in February, announced she was three months pregnant at the beginning of April.
Barbet and Traquair, who also started at Five News in February, will front the 5pm and 7pm bulletins on different days.
"Matt and Isla are the Young Turks of TV news – they are a dynamic duo who represent all that is great about Five News," said editor David Kermode.
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