The Girls of the Playboy Mansion star, who announced her pregnancy in August, tweeted a photograph of herself in her hospital bed.
© Instagram / @hollymadison
The image also showed Madison receiving fluids from an IV.
"Almost 7 months and morning sickness took hold!" she wrote alongside the picture. "Glad to be otherwise ok, tho."
Madison also thanked her fans for their support, saying: "Thank you for all the get well wishes! Keeping me entertained-forgot to bring a book with me."
Madison, who confirmed in October that she is expecting a daughter, has previously revealed that she is considering some "unusual" names for her new addition.
