A baby conceived in the hope that she can serve as a bone marrow donorfor her teen-age sister appears to have nearly identical bone marrow cells and may be able to save her sister's life.
"This is our baby. This is our miracle baby," exulted Abe Ayala after hearing doctors say that his unborn baby's marrow matches that of his 17-year-old daughter, Anissa, who is afflicted with leukemia.
Only a bone marrow transplant can save her.
"We are all very, very blessed," sobbed Mary Ayala, 43, who is due to give birth to a girl in mid-April. "I feel my baby is a blessing from God."
At a family press conference on Friday, Anissa cried when asked about her parents' decision to have the new baby.
"A lot of people think, 'How can you do this? How can you be having this baby for your daughter?"' she said. "But she's my baby sister and we're going to love her for who she is, not for what she can give me."
Medical experts caution that Anissa's unusual case may give false hope to desperate parents of young leukemia patients. There is only a one-in-four chance that siblings with the same mother and father will have closely compatible bone marrow cells, and conceiving a baby solely for the purpose of donating bone marrow to a sibling raises ethical issues.
Anissa was found in 1988 to have chronic myelogenous leukemia, a form of leukemia that can be cured only with a bone marrow transplant, according to doctors who are caring for her at City of Hope National Medical Center in Duarte, Calif. Her parents spoke to reporters at the Life-Savers Foundation of America, which is based in Covina, about 20 miles east of Los Angeles, and which recruits donors for the 9,000 Americans who are awaiting bone marrow transplants.
In chronic myelogenous leukemia, a bone marrow transplant from a compatible bone marrow donor has a 70 percent chance of a cure, said Dr. Stephen Forman, director of hematology and bone marrow transplantation at the hospital.
A search by the National Marrow Donor Program for unrelated donors and testing of Anissa's family members failed to locate a suitable donor.
Last fall, when Mary Ayala was about three months pregnant, she underwent amniocentesis. In the procedure, an obstetrician inserts a needle into the uterus through the abdominal wall. A sample of the fluid from around the fetus, which contains fetal cells, is obtained and analyzed.
Amniocentesis is normally recommended for all pregnant women over the age of 35 because of the increased risk of birth defects in babies of older mothers. As part of the test, the sex of the fetus is learned.
In the Ayala case, the physicians also determined the tissue type of the fetus. The results of the tissue typing indicated that the siblings' bone marrow cells would almost certainly be compatible, doctors said Friday.
"We knew about (the positive results) within the past month, but the family didn't want it out because of all the questions coming up, the ethical questions," said Dr. Patricia Konrad, a pediatric oncologist at City of Hope who is caring for Anissa.
Konrad and other medical experts not connected with the case have expressed concern about the vexing issue of conceiving a baby solely for the purpose of trying to save another sibling's life. Konrad warned that the Ayalas' experience may not be an example for other parents to follow.
"I would never advise a family to have a baby for that purpose," she said. "Besides, there are very few families with identical situations."
A Seattle tumor specialist recalled other isolated attempts, both
successful and unsuccessful, in which a child was conceived with the hope that it would be a bone marrow donor.
Dr. Patrick Beatty, a medical oncologist and head of the tissue typing laboratory at the University of Washington's Fred Hutchinson Cancer Research Center, knows of several cases in which a baby conceived as a possible donor turned out to have compatible bone marrow. In those cases, however, laboratory tests to determine the compatibility of the bone marrow were not performed until after the child was born.
"This (case) disturbs me a lot," Beatty said.
When the baby is at least 6 months old, doctors plan to destroy Anissa's diseased bone marrow with chemotherapy and radiation. Then they plan to obtain marrow from the baby's hipbone and inject it into Anissa through a vein, similar to a blood transfusion. The marrow cells travel through the bloodstream to the bone marrow, where they grow.
If the leukemia disappears and does not recur within two years after the procedure, Anissa will be considered completely cured, Forman said.
Doctors said the search for an unrelated donor for Anissa will continue, because there is a chance she will need medical help before her sister is 6 months old.
Arthur Caplan, director of the Center for Biomedical Ethics at the
University of Minnesota in Minneapolis, is concerned about the effect on the donor child if the procedure fails.
"That's a terrible burden to place on the person," he said. "It means they failed the purpose for which their parents conceived them."