The British singer is expecting her first child, a son, with her soccer star fiance Wayne Bridge later this year (13) and the mum-to-be has been told she needs to rest up as she nears her due date.
As a result, she will leave it up to her bandmates Una Healy, Rochelle Humes, Mollie King and Vanessa White to entertain fans at their forthcoming gigs across the U.K., starting with a show on Saturday (10Aug13) in Kent, England.
Taking to her Twitter.com blog on Thursday (08Aug13), Sandford writes, "Hey guys, really sad I won't be there for the next few gigs, as I've been advised not to perform by my doctor until after the baby arrives. But don't worry, I know my other 4 Sats (sic) will totally rock it while I'm resting the bump. I'll be back Asap (as soon as possible)!"
Sandford announced her pregnancy news in May (13), weeks after becoming engaged to Bridge.
The Saturdays are no strangers to performing as a foursome during pregnancies - Healy had to sit out some shows last year (12) when she gave birth to daughter Aoife Belle last year (12), while Humes welcomed her little girl, Alaia-Mai, in June (13).