It's the flu, not morning sickness, that has Christina Aguilera calling in sick.
The singer, who is pregnant with her first child, has scuttled two tour dates in Australia after coming down with "a bad flu virus" that left her on bed rest.
"Doctors have confirmed Christina has a viral upper respiratory tract infection with a high fever and abnormal coughing,'' promoter Michael Gudinski of the Frontier Touring Company said in a statement.
"They have prescribed complete bed rest for the next few days.''
Gudinski said several members of Aguilera's road crew had also fallen ill. The promoter hoped the canceled dates—Aguilera called off shows in Melbourne on Saturday and Monday—would be rescheduled, but refunds will be available.
"Unfortunately, I have fallen ill with a bad flu virus. This is one of the best cities in the world to perform in and I am truly disappointed that I won't be able to share my show with you all,'' the 26-year-old songbird said.
"Thank you for all of the continued love and support and I hope to perform for you all again next time.''
The "Come On Over Baby" performer is in the final days of her Back to Basics world tour, which wraps in Auckland with shows Thursday and Friday. So far those gigs are still on.
Although Aguilera has not yet publicly announced it, E! News learned earlier this month that the five-time Grammy winner and hubby Jordan Bratman are expecting their first child together this winter.