A brain-dead woman who gave birth yesterday to a baby daughter at a Northern Virginia hospital died today after she was taken off life support, doctors and family members said.

Susan M. Torres, 26, her body ravaged by cancer that spread to her brain and other vital organs, was disconnected from the ventilator and other machines that kept her alive. Her death came a day after doctors delivered a 1 pound, 13 ounce girl by Caesarian section. The baby, named Susan Anne Catherine Torres, appeared to be healthy and is being cared for and observed in the neonatal intensive care unit of the Virginia Hospital Center in Arlington, doctors said.

Archie McPherson, chief medical officer at the hospital, told a press conference that Torres's husband, Jason Torres, "made the decision this morning to withdraw artificial life support systems" from his wife. It was a decision supported by doctors and other relatives because of the irreversibility of her condition.

A statement issued by Justin Torres, the brother of Jason, expressed gratitude for the public support the family has received and asked for people's "continued prayers for the newest member of our family."

He said his niece "continues to do well" in the neonatal intensive care unit.

"This is obviously a bittersweet time for our family," Justin Torres said. "We are overjoyed at the birth of baby Susan and deeply grieved at the loss of her mother." He said the birth resulted from "Susan's determination," adding that his sister-in-law "was always the toughest person in that ICU room."

McPherson said doctors decided to deliver Susan Torres's baby yesterday after determining that "the risk of continuing her pregnancy had become greater than the risk of delivering the baby at the then-gestational age of 27 weeks." He said doctors and administrators were "delighted at the successful delivery."

At the time of the delivery, Torres's cancer was spreading rapidly, and doctors were having more and more difficulty maintaining her vital organs in what amounted to a race between the disease and the baby's development to an age that gave hope for survival.

Christopher McManus, a doctor coordinating Torres's care, offered the family both condolences and congratulations. "I hope they take solace in the fact that giving her life for the birth of this baby demonstrates the best that anyone can do for another human being," he said.

Susan Torres, a vaccine researcher at the National Institutes of Health and mother of a 2-year-old son, collapsed three months ago while dining at home from a stroke caused by an undiagnosed brain tumor. She was 15 weeks pregnant.

After she was admitted to the hospital and pronounced brain dead, her husband faced the choice whether to let her die or try to keep her alive artificially long enough to give birth to a premature baby, who might be disabled. He devoted himself to trying to ensure the baby's survival, quitting his job as a commercial printing salesman and moving into his wife's hospital room to help care for her.