This year’s Met Gala was a celebration of the late designer Karl Lagerfeld, the longtime force behind Chanel, Fendi and other global luxury brands. While many celebrities dressed in their best renditions of his Lagerfeld’s iconic personal style, Serena Williams stunned the red carpet in more ways than one: by revealing her baby bump.

Just moments before walking the red carpet, Williams took to Instagram to share a photo of her custom Gucci gown. But it was what the dress revealed — and Williams’ caption — that got the attention.

“Was so excited when Anna Wintour invited the 3 of us to the Met Gala,” Williams wrote.

Williams announced her retirement from tennis last year in a heartfelt letter to Essence Magazine. While the decision wasn’t easy, Williams wrote, she wanted to focus more on other aspects of her life.

“I’m here to tell you that I’m evolving away from tennis, toward other things that are important to me. A few years ago I quietly started Serena Ventures, a venture capital firm. Soon after that, I started a family. I want to grow that family,” she said at the time.

Williams and her husband, Reddit co-founder Alexis Ohanian, welcomed their first child in 2017.