Was so excited when Anna Wintour invited the 3 of us to the Met Gala," Williams said on Instagram just before she arrived at the Metropolitan Museum of Art, decked out in a black and white gown, for fashion's biggest night of the year.
In the photos, the 41-year-old tennis great is seen posing in a black and white gown with her husband Alexis Ohanian, the founder of Reddit, and cradling the baby bump.
Williams and Ohanian are already parents to Olympia, born in September 2017.
Last year, Williams, who won 23 singles Grand Slam titles and multiple Olympic gold medals throughout her long career -- bid an emotional farewell to tennis at the US Open.
"I'm ready to, like, be a mom, explore a different version of Serena," she said at the time.
Last year, in an essay for Elle magazine, Williams described the difficulties she experienced in giving birth to Olympia, eventually via emergency C-section, and how she suffered blood clots in her lungs shortly thereafter.
Williams was not the only person to reveal a baby bump at the Met Gala; model Karlie Kloss also confirmed her second pregnancy at the event.
