The 7.30 host announced the news on Monday morning on Twitter, telling her 85,000-odd followers she is pregnant.

“I'm delighted to say that my husband and I are expecting baby number 2, due early next year,” posted the forty-year-old who has been married to animator Phil Willis for more than 16 years.

I'm delighted to say that my husband and I are expecting baby number 2, due early next year. — Leigh Sales (@leighsales) September 16, 2013

Sales also revealed that, before breaking the news, she had a bucket by her side to cope with a bout of morning sickness while conducting a live election campaign interview.

A consummate professional, she thanked interviewees – Labor senator Penny Wong and her Liberal counterpart senator Mathias Cormann – for keeping mum.

I did have to do one live campaign interview with a bucket next to me. 10 points to @SenatorWong and @MathiasCormann for their discretion! — Leigh Sales (@leighsales) September 16, 2013

It is not the first time the Walkley award-winning journalist has had to juggle her high-profile job with the sometimes messy realities of motherhood.

In an interview with Sunday Life last year, she spoke of returning to work after having her son Daniel, now 18 months old: "You try to arrange things still, like, 'I'll get up in the morning and he'll have his breakfast and while he's eating I'll read the papers and do this and do that', but the reality is he needs a nappy change and he's grabbing the iPad and ... 'Arrrgghh!'

"I remember being about to start an 8.30am conference call and he threw up all over me."

But, such incidents have taught her to flow with the unpredictability of her role while staying sharp, she said.

"I find that hard – letting go of being on top of everything. But really, the nature of a big news job like mine is you have no control. Something enormous could happen right now and this interview would have to end and I'd be off to talk to someone about a nuclear power plant leakage or whatever.

"Maybe the baby is teaching me to roll with the punches and go with the flow. It is not about controlling everything, but just doing the best I can."

Today, she told Fairfax Media: "I tend to see being a mother and what I do for a job as two entirely separate things so I don’t feel like either area informs the other.

"Except I will say that trying to get an eighteen-month-old to do things he doesn’t want to do is about a million times harder than a live TV interview with a Prime Minister."

While Sales returned to work only five months after having Daniel, she may not do this time around.

"I'm not sure how I'll time my return to work," she said. "I think it's always tough, no matter when you come back.

"I do feel pretty daunted about juggling a two-year-old and a newborn with hosting 7.30, but luckily I have the best husband in the world to share the load.  Daniel was also a very, very laidback baby and a great sleeper so I'm praying for another one exactly the same."

Sales is widely regarded to be one of Australia's most respected journalists.

A former US correspondent for the ABC and host of Lateline, Sales won a Walkley award for best interviews following her razor sharp cross examination of then opposition leader Tony Abbott.

The published author took over the prestigious reins of 7.30 from veteran presenter Kerry O'Brien in March 2011.

The ABC has responded to the news of Sales' pregnancy, which was planned, saying: "We are delighted to congratulate Leigh and her family on this exciting news."

They informed Fairfax that a maternity replacement for Sales will be announced before the end of the year.