The condition of the 23-year-old gangrape victim deteriorated late on Tuesday as her pulse rate declined considerably. It, however, recovered soon.
She was being flown from Delhi to Singapore late on Wednesday, reports suggested.
She, however, continued to be critical but stable, doctors attending on her said.
The woman was gangraped by six men on a bus on December 16.
Several surgeries, including the removal of her small intestines, and stomach washes to stem the fast-spreading infection were carried out all through last week but haven't helped much, said to the doctors.
The medical bulletin on her health by the doctors at Safdarjung hospital, where she was being treated, was postponed twice on Wedneday as heart specialists, including Naresh Trehan from Medanta, the Medicity, attended on her.
According to sources, her condition had deteriorated late on Tuesday as she had suffered a "thromboembolic attack"- a developing clot in her artery - with her pulse rate dropping sharply, but she recovered within minutes.
Sources said her pulse rate has suddenly dropped to below 50 per minute. "Her condition continues to be critical but stable," a senior doctor said while confirming her thromboembolic attack on Tuesday.
The medical bulletin on the victim's health was to be issued at 4.30pm but was postponed till 6.30pm, only to be cancelled again by the hospital administration.
Senior health officials, including the director-general of health services, held consultations with doctors attending on her. There was heavy police deployment outside the hospital.