Chelsea Clinton is a mom again.
The former first daughter took to Twitter on Saturday to announce the birth of her son, her first with hedge fund manager husband Marc Mezvinsky.
"Marc and I are overwhelmed with gratitude and love as we celebrate the birth of our son, Aidan Clinton Mezvinsky," Clinton wrote.
Aidan's older sister Charlotte was born in September 2014.
Hillary Clinton retweeted her daughter's joyful message and issued a joint statement with former President Bill Clinton.
"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," they said.
The presumptive Democratic nominee for president had no campaign stops on her schedule for Thursday or Friday, nor does she have events planned over the weekend.
Chelsea Clinton and Marc Mezvvinsky live in New York City.
Clinton's friend Ivanka Trump also gave birth to a child while one of her parents campaigned for president.
Ivanka and her husband Jared Kushner welcomed their third child. Theodore James Kushner is presumptive Republican presidential nominee Donald Trump eighth grandchild.