The new mom wore the Fuchsia Knot Front Seraphine Dress which retails at $79 in the United States.
Given the dress' high popularity, the company said in a statement that future orders will be dispatched commencing on September 16.
According to Seraphine, Middleton also owns a printed version of the dress called the Blossom Knot Front Lavender Maternity Dress which retails at $85. The site also states that due to high popularity of the style current orders of the garment will dispatch starting September 2.
The Duchess turned Princess has become quite the fashion icon since becoming part of the royal family. Her classic yet affordable style has been so well received by the public that one her favorite designers, Issa London, has teamed up with Banana Republic to create a capsule collection featuring dresses that mirror Middleton's iconic ensembles.