The former girlfriend of Playboy boss Hugh Hefner admits the incident has left her shaken because she had no idea she would suffer such symptoms in her final trimester.
She tells U.S. news show Entertainment Tonight, "When it started happening really late (in my pregnancy) and I was really vomiting a lot during the day, it freaked me out.
"I was told to go to the doctor and get an IV (intravenous drip) and everything. So, that was kind of scary to me just because it seemed like something so unusual, something that I hadn't read about. But everything's OK so far, so that's good."
Now Madison, who is expecting the tot with her party promoter boyfriend Pasquale Rotella, is counting down the days to her due date early next year (13).
She adds, "I'm excited to get through these last months of pregnancy. Hopefully no more scares."
Madison wasn't the only expectant mum hospitalised this week (03Dec12) - British royal Catherine, Duchess of Cambridge has been receiving medical treatment for a similar condition, hyperemesis gravidarum, following her baby announcement on Monday.