The 33-year-old beauty and Seal welcomed their son Henry into the world last September--a sister to Klum's two-year-old daughter Leni from a previous relationship with Flavio Briatore--and insisted they would wait before adding to their family again.
But today Seal wrote on Klum's Web site: "It gives me great joy to announce that Heidi, Leni, Henry and I are expecting a new addition to our ever increasing family.
"We all feel both excited and fortunate to be able to share this experience once again."
According to reports, Klum was "just starting to show" at the Council of Fashion Designers Awards (CFDAs) earlier this month.
Article Copyright World Entertainment News Network All Rights Reserved.