Weekend TODAY host Deb Knight announces pregnancy live on air

Weekend TODAY host Deborah Knight has announced she is pregnant with a baby girl.

The 9NEWS presenter and journalist made the surprise announcement on this morning's program saying: "Quite unexpectedly, I'm expecting."

She said she is currently 14 weeks along and the pregnancy was a complete surprise as she had used IVF to fall pregnant previously.

Knight and her husband Lindsay Dunbar have two children, Darcy and Elsa.

Weekend TODAY newsreader Wendy Kingston, who joins Knight on the couch each Saturday and Sunday morning, announced she was pregnant with her third child in June.