Fans were full of congratulations for Fraser, who is currently on tour in Australia.
"Babies are such a blessing. Congrats Brooke! Get ready for a whole new world," wrote one.
"Something's in the water - congratulations!" wrote another.
Rumours had spread after Fraser cancelled a 10-date nationwide tour across March and April without giving a specific reason why.
A statement released via Fraser's Facebook page said all shows had been cancelled due to "unavoidable scheduling conflicts".
It now seems those conflicts were that the shows coincided with her pregnancy.
At the time, one fan said: "We were speculating re a baby announcement lol."
Fraser has promised to reschedule those cancelled shows.
Ligertwood and Fraser married in 2008. She released her fourth album Brutal Romantic last year.
Read more: Brooke Fraser's new phase: No more nice girl
- nzherald.co.nz