Labor MP Kate Ellis is pregnant with her second child.

Outgoing Labor member for Adelaide Kate Ellis is pregnant with her second child.

The announcement, made by her husband, comes just a week after she formerly resigned from parliament, citing family reasons.

The 39-year-old’s husband David Penberthy shared the happy news with listeners on his Adelaide radio show, 5AA breakfast, on Wednesday morning.

Penberthy was chatting to co-host Will Goodings in between an interview with South Australia Premier Jay Weatherill and talking talk back calls when he revealed the pregnancy, news.com.au reports.

Listen: Kate Ellis talks to Mamamia about the day in the life of a politician and a new mum. Post continues… 

Goodings was so taken aback he asked if Penberthy “thought the mics were off”, though it is not clear if this was the case.

Shortly after, Ellis confirmed the news to Fairfax Media, saying she and her husband were “happy and excited” for their second child, who will join their son Sam, as well as two children from Penberthy’s previous relationship.

She told the Sydney Morning Herald the pregnancy was not the reason she chose to resign.

“I was really honest last week about things,” Ellis said.

“Whether or not I was pregnant with this child made no impact on that decision.”

Last week Ellis told reporters she decided to quit politics to spend more time in Adelaide with her son Sam.

"I don’t want to be spending 20 weeks of the year in a different state to my child," she said.

"It’s really hard. I’m really sad about it because I know how lucky I am to have a job that I love and I’m so grateful for the faith that the community has put in me.

"It’s sad to have to leave, but if this government runs full term I would have had the opportunity to spend 15 years as the Member for Adelaide, and that’s pretty substantial."

Ellis said she will stay in parliament until the end of her term, so as to not force a by-election.