The Wipeout host is currently expecting her first child with husband Nick Lachey and feels it would be too dangerous to fly as she advances further into her pregnancy.
"I can't believe you are allowed to fly pregnant all the way up to 36 weeks! Then no more! That's pretty far along," Vanessa tweeted on Wednesday before heading to New York City.
"P.S., I don't intend to be flying close to 36 weeks! After my Dr.'s OK and compression thigh highs in tow, I'm ready for one last work trip."
Vanessa recently said that she is "excited" to become a mother and is looking forward to achieving a balance between career and motherhood.
Nick confessed last month that he and Vanessa are attempting to enjoy their "last bit of freedom" before the baby's arrival.