Samantha Orobator, 20, was sentenced in June to life in prison after pleading guilty to drug trafficking. Police said they found 1.5 pounds of heroin in 68 capsules on Orobator's body when she was arrested last August at Vientiane airport on her way to Australia.
She was scheduled fly to Bangkok on Thursday evening and then board another flight to London.
Heroin trafficking is punishable in Laos by death, but Orobator was spared because Lao law does not allow the execution of pregnant women.
Orobator became pregnant while incarcerated and Lao officials have asserted that she may have artificially inseminated herself while behind bars. She will be 36 weeks pregnant on Aug. 12 — after which she would likely be unable to take an international flight.
Under a pact signed in May by Laos and Britain, Orobator could be extradited to serve her time in Britain, though it is unlikely she will serve a life sentence. The two countries signed a memorandum of understanding last week bringing the agreement into force.
Lao Foreign Ministry spokesman Khenthong Nuanthasing said Wednesday that Orobator was being transferred with the assurance she would serve the rest of her sentence in Britain.
Orabator's mother Jane, who lives in Dublin, has fought to have her daughter transferred out of Laos since she was arrested. She told the Press Association news agency Wednesday that she was "shocked but delighted" that her daughter's ordeal was nearly over.
"I just want her to come back to the U.K., that is my first desire," she said. "One step at a time, I just want her to have her baby here."