The 'Home' singer's little boy is set to undergo treatment for liver cancer.
JLS congratulate Una on baby news
JLS are one of the first to give their best wishes to The Saturdays' Una on her pregnancy.
The boys are good friends with The Saturdays, they've spent a lot of time together, and Marvin and Rochelle's relationship has ensured they remain close.
So on hearing the latest news that Una Healy and her boyfriend Ben Foden are expecting a baby , JB tweeted to congratulate the happy couple.
"Awwwww!congratulations @unahealy :D ," he posted on the JLS Official Twitter. "So chuffed for you and ben!BIG love,Jaybes x."
And Rochelle's boyfriend Marvin was quick to follow.
"Massive congrats to @unahealy and Ben..amazing news!" he tweeted. "A little Saturday baby on it's way! All the best from Marv and all the boys x."
The Daily Mirror say Una is "delighted" with the news, despite the fact that it was a surprise.
The Saturdays' All Fired Up tour kicks off later this year, when a new album is also due to be released.
|Expecting: The Saturdays' Una and England Rugby star Ben Foden.|
The star headed straight from the jungle to panto...but clearly hadn't had time to learn her lines!