Credit: Billy Farrell/BFAnyc/Sipa USA

Baby on board!

A pregnant Lily Aldridge was all smiles at the American Beauty book launch in NYC Thursday.

Clad in a floor-length Proenza Schouler maxi dress and towering Alaia sandals, the fist-time mommy to be showed off her growing baby bump.

Back in December, the Victoria's Secret model announced that she and husband Kings of Leon rocker Caleb Followill are expecting their first child together.

The couple, who wed in May, told Us Weekly in a joint statement, "We are thrilled to announce that we are expecting our first child together. We can't wait to meet the new addition to our family."

Aldridge, 26, isn't the only Victoria's Secret Angel to have a baby on board.

Alessandra Ambrosio is currently pregnant with her second child with fiance Jamie Mazur (they're parents to 3-year-old Anja), and fellow Brazilian Adriana Lima her Serbian basketball player hubby Marko Jaric are also expecting a brother or sister to daughter Valentina, 2.