Pregnant Chelsea Clinton rocked black leather pants during an appearance in NYC with mother Hillary Clinton on Thursday, June 12 Credit: Christopher Sadowski/Splash News and Pictures

Chic pregnancy style! Pregnant Chelsea Clinton stepped it up in the wardrobe department during an appearance with mother Hillary Clinton at the 2014 Wildlife Conservation Society Gala at the Central Park Zoo in NYC on Thursday, June 12.

The mom-to-be, 34, rocked black leather pants and concealed her growing baby bump with a matching long-sleeve top as she stood next to the former First Lady and Secretary of State during the event. She accessorized with Christian Louboutin heels and kept her makeup natural.

Clinton announced she and husband Marc Mezvinsky were expecting their first child during the Girls: A No Ceilings Conversation event in NYC last April.

"One more thing to say very quickly," she said. "Mark and I are very excited that we have our first child arriving later this year. I certainly feel all the better whether it's a girl or a boy that they'll grow up in a world with so many strong female leaders…"

Hillary replied: "I'm expecting a grandchild which I'm very excited about. We're very excited about what's happening in our family but we're also very excited about what we're doing."

Dad Bill Clinton, for his part, took to Twitter to say his peace. The former President gushed: "Excited to add a new line to my Twitter bio...grandfather-to-be!" he gushed.