Presidential hopeful Hillary Clinton is a grandmother twice over, the AP reports. Chelsea Clinton announced Saturday that she has given birth to her second child, son Aidan. The 36-year-old daughter of former President Bill Clinton and current presumptive Democratic presidential nominee Hillary Clinton and her hedge fund manager husband Marc Mezvinsky have a 20-month-old daughter, Charlotte. Both Charlotte and Aidan were born at Manhattan's Lenox Hill Hospital. On Twitter, Chelsea Clinton said the couple is "overwhelmed with gratitude and love." Aidan is the second baby to be born to the child of a presidential candidate this year. In March, presumptive Republican nominee Donald Trump's daughter Ivanka gave birth to her third child, son Theodore James. (More Chelsea Clinton stories.)