Gwen Stefani and Gavin Rossdale want the sex of their unborn child to remain a mystery until the singer/actress gives birth this summer.

The couple only wants to discover the gender of their second child in the delivery room when Stefani goes into labour, just like when she welcomed their two-year-old son Kingston into the world in 2006.

Speaking to Los Angeles DJ Ryan Seacrest on his KIIS-FM radio show on Wednesday, Rossdale said, "We don't know (the baby's sex). It was a surprise last time so we're kind of working on that this time."