Nominating country singer Kacey Musgraves, fiancé Wladimir Klitschko and "her unborn child" to take the challenge next, Panettiere was doused with ice cold water with a little help from Dancing with the Stars pro Derek Hough.
"Couldn't figure out how to post it on @haydenpanettier twitter so I'm posting it for her . #als #icebucketchallenge (Hayden shortly went into labor after this ) Jus kiddin," Hough posted on Instagram.
Though unlike Saldana -- who cited her obvious baby bump as the reason she couldn't participate in the challenge herself and nominated her husband Marco Perego instead -- Panettiere was actually game to get doused with freezing cold water.
"Yup, that's cold," she smiled.
The ALS Ice Bucket Challenge has turned into a celebrity phenomenon, and has raised over $13 million in donations since July 29.
Check out the best celebrity ALS Ice Bucket Challenges videos, including ET’s own Nancy O’Dell’s, in the video below.