Chelsea Clinton and her husband Marc Mezvinsky welcomed their second child – son Aidan Clinton Mezvinsky on Saturday, June 18. The 36-year-old former first daughter announced the news via Twitter.

Aidan joins 20-month-old big sister Charlotte. Presidential hopeful Hillary Clinton and her husband, former president Bill Clinton, also confirmed the news in a statement.

"We are overjoyed to be grandparents again with the arrival of our grandson, Aidan Clinton Mezvinsky, born on Saturday, June 18, 2016. We are all over the moon as Chelsea and Marc welcome Charlotte’s little brother to the world and grateful for our many blessings. Chelsea and Aidan are both doing well and enjoying this very special time together."