Hillary Clinton's daughter Chelsea Clinton blessed with second baby

Melbourne: Chelsea Clinton, who is already a proud mother to daughter Charlotte, turned mommy to a new baby boy.

The daughter of US Democratic presidential candidate Hillary Clinton and former President Bill Clinton, announced the arrival of newborn son Aidan Clinton Mezvinsky late Saturday morning on Twitter, reports News.com.au reports.

In a statement, elated Bill and Hillary said, "We are overjoyed to be grandparents again with the arrival of our grandson. 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."

Clinton and her husband Marc Mezvinsky, who tied the knot in August 2010, revealed in December that she was due to give birth to a second child via Twitter, writing "Next summer, Charlotte is going to be a big sister!"