"Rei Kawakubo/Comme des Garcons: Art Of The In-Between" Costume Institute Gala - Arrivals

NEW YORK, NY - MAY 01: Serena Williams attends the "Rei Kawakubo/Comme des Garcons: Art Of The In-Between" Costume Institute Gala at the Metropolitan Museum of Art on May 1, 2017 in New York City. (Photo by Karwai Tang/WireImage)

Karwai Tang

Over the weekend, Serena Williams celebrated the upcoming arrival of her baby with a star-studded, '50s-inspired baby shower (guests included Ciara, Lala Anthony, Eva Longoria, and Kelly Rowland.)

Of course, no baby shower is complete without an epic squad pic. Serena Williams took to her Instagram to share a group shot of the women, all donning poodle skirts and/or other '50s inspired clothing. "When you and your crew go so far back to the 50's. Even then they had your back," the tennis star captioned.

Anthony and Ciara also took to their social media accounts to share photos from the special day. Dressed as Rosie the Riveter, Anthony flexed her muscles for one snapshot.

Williams, who's engaged to Reddit co-founder Alexis Ohanian, accidentally announced her pregnancy with a Snapchat photo of her baby bump back in April. Her beautiful bump also graced the cover of Vanity Fair's August issue. In the issue's accompanying profile, Williams reveals how she found out about her little bun in the oven just a few days before the 2017 Australian Open in January (which she won), as well as how she's preparing for motherhood.

"How am I going to play the Australian Open? I had planned on winning Wimbledon this year," she told VF. "It just doesn't seem real. I don't know why. Am I having a baby? If you would have told me last year in October or November that I would have a baby—not be pregnant but have a baby—I would have thought you were the biggest liar in the world. This is kind of how I am right now. This is happening sooner than later, and it's going by so fast."

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Watch: Elizabeth Banks’ Best Birthday Was Also a Baby Shower