The Heroes and Nashville star is expecting her first child with her fiancé, boxer Wladimir Klitschko.
Hayden, 25, wore next to no make-up except for a bit of lip gloss as she made her way through the terminal, stopping briefly to pet a fan's dog.
At the recent Emmy awards the star - who confirmed her pregnancy in June - revealed she is expecting a baby girl.
She said at the time: "I'm thrilled! I can't wait for her to come out!"
As for names, Hayden is considering a moniker which will represent her American heritage and the ancestry of her Ukranian partner.
She told E!: "We have to make sure that it is American and Ukrainian all at the same time. That's a little rough...we're still working on it."
Hayden and 36-year-old Wladimir's relationship has been on-and-off since they met at a book launch party in 2009.
They officially split up in 2011, but were back together by the spring of 2013 and quickly got engaged.
At the time, Hayden said she felt she was 'born to be a mother'.
She said: "Sometimes people speak about [having kids] like, 'Your life ends - you're never going to be able to do anything again!' And I'm like, 'What are you talking about?
"Motherhood is the most beautiful, exciting thing, and there's nothing that I feel like I can't accomplish while having children in my life."
Hayden, who is 5ft 2in, joked about what her children with 6ft 6in heavyweight champ Wladimir might look like: "He's got bowlegs and I've got knocked knees, so they're going to have straight legs. And they'll be normal height!"
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