The star adorned her Balenciaga by Nicolas Ghesquière gown with a cascading diamond necklace by L'Wren Scott and jeweled Bottega Veneta clutch.
Alba (in Cartier jewelry) told PEOPLE her feathered Marchesa "leaves room for the belly.... I feel good [in it]!"
The star (she's having a boy!) wore a Dries Van Noten dress with an embellished neckline and Lorraine Schwartz platinum jewelry.