She also filmed a pregnancy reveal video directed by none other than her friend Lena Dunham, in which she shows off her baby bump and includes footage from her ultrasound scan.
Ratajkowski appears nude in the video and narrates over the footage, saying: "There's a quietness that comes with pregnancy, a humbling. I'm listening for you. I'm full of wonder."
She then says, "I cannot wait to see who you will be."
The model wrote in the caption, "I'll cherish this video as long as I live. Link in bio to watch. @voguemagazine.
"Thank you to my brilliant and very generous friend @lenadunham for her vision and commitment to directing this. I'm so grateful.
"And thank you to my other wonderful friend @eccopn for his music and to @dschneids for her editing! You all made this the most special. Written and filmed by me. Shot at home."
Ratajkowski chose not to reveal the sex of her baby, telling Vogue that her child "won't know the gender until they are 18 and that they'll let us know then. Everyone laughs at this."
She went on to say that she liked the idea of forcing as few gender stereotypes on her child as possible.
"But no matter how progressive I may hope to be, I understand the desire to know the gender of our fetus; it feels like the first real opportunity to glimpse who they might be.
"As my body changes in bizarre and unfamiliar ways, it's comforting to obtain any information that might make what's coming feel more real."
Ratajkowski admitted she'd automatically imagined having a daughter.
"I remember playing as a child, holding baby dolls and picturing myself with a future best friend: something like the American Girl doll I owned, who had brown eyes and brown hair to mirror my own features, a smaller version of myself," she said.
She married producer Bear-McClard at a courthouse in 2018 after a brief romance.
