A leukemia-stricken teenager who received bone marrow from the baby sister conceived to save her life won't know for another month whether the transplant succeeded.

Anissa Ayala, 19, has chronic myelogenous leukemia and has been hospitalized since May 22 at the City of Hope National Medical Center. Before Tuesday's marrow transplant, Anissa underwent intensive chemotherapy to destroy her cancerous bone marrow.The donor marrow was taken from her 13-month-old sister, Marissa.

"About a pint-and-a-half of marrow is obtained from the donor, using a special needle that draws off the marrow from the back over the pelvic bone area," said Dr. Stephen J. Forman.

Doctors said Anissa would be hospitalized at least four more weeks while her immune system recovers from radiation and chemotherapy.

As for Marissa, he said, "The baby is home and well; she went through it great."