Chelsea Clinton, daughter of U.S. Democratic presidential candidate Hillary Clinton and former President Bill Clinton, announced on Saturday the birth of her second child with husband Marc Mezvinsky.

Aidan Clinton Mezvinsky was born on Saturday to Clinton and her investment banker husband, according to a statement released by the proud grandparents. His older sister, Charlotte Clinton Mezvinsky, was born on Sept. 27, 2014.

"We are all over the moon as Chelsea and Marc welcome Charlotte's little brother to the world and grateful for our many blessings," Hillary and Bill Clinton said in the statement.