Time is running out for Elizabeth Holmes, the convicted founder and CEO of Theranos, the now-defunct blood-testing company.

In an order late Monday night, U.S. District Judge Edward Davila denied Holmes' motion for bail pending appeal.

The order means that, unless a higher court intervenes, Holmes must surrender to federal prison authorities on April 27 to begin serving an 11-year sentence for wire fraud and conspiracy.

Holmes had sought a temporary reprieve on the theory that numerous evidentiary rulings made by Davila during Holmes' four-month trial in the fall of 2021 would be reversed on appeal.

The bulk of the challenged rulings related to Holmes' false statements to investors regarding whether Theranos' much-touted fingerstick blood-testing technology actually worked.

Davila wrote that even if an appellate court eventually concludes that some of the rulings were erroneous, the many other misrepresentations by Holmes, "such as those regarding the company's financial status, reliance on third-party and commercially available devices, partnership with Walgreens, and validation by pharmaceutical companies," meant that reversal of a single evidentiary decision was not likely to lead to reversal of her conviction.

Although refusing to delay Holmes' surrender date, Davila rejected arguments by the prosecution that she posed a flight risk.

Prosecutors claimed that a planned one-way trip to Mexico -- booked for the couple by Holmes' partner, William Evans, while the jury was deliberating -- demonstrated Holmes' intent to flee the jurisdiction.

"Booking international travel plans for a criminal defendant in anticipation of a complete defense victory is a bold move, and the failure to promptly cancel those plans after a guilty verdict is a perilously careless oversight," Davila wrote.

But Holmes, he said, was unlikely to flee, given her two young children, the $500,000 bond secured by her parents' home, and the fact that her notoriety would make her instantly recognizable.

Even so, Davila concluded, Holmes had not raised a "substantial question ... that was likely to result in reversal or an order for a new trial."