A woman's eggs decline in quality as they age. In studies during the 1980s, doctors observed that women after 45 rarely got pregnant with their own eggs, and after 55, they almost never conceived.
But later studies of women who received egg donations from a sister, after experiencing early menopause, suggested the uterus does not age, said Paulson.
"In the 1990s, a light bulb went on," he said. "Egg donation is not influenced by the age of the mom. It doesn't matter how old the uterus is. The new limit on motherhood is the energy level and willingness to have a child."
Most doctors draw the line for egg donation at age 55, when the rate of obstetrical complications begins to rise, according to Paulson. At 55, pregnant women experience high blood pressure 25 percent of the time; after that, the rate goes up to 60 percent.
To be eligible, women are carefully screened for potential health problems — especially, cardiovascular disease.
Paulson debunked the theory that Bousada de Lara's illness may have been caused by fertility drugs, which are administered to both the egg donor and the recipient.
"There are a lot of predictors of longevity, and we don't exclude people on the basis of age," he said. Older woman have "special" reasons for wanting a child, he said.
Many are first-time mothers who have found love later in life; others have married younger men who have not yet had children; still others are couples whose older child has died.
Bousada de Lara was quoted, saying, "I have wanted to be a mother all my life, but I never had the opportunity, or met the right man."
Doctors have found no difference in stress levels among younger and older mothers. A healthy woman at age 50 has 35 more years of life expectancy, according to Paulson.
"Typically, they are in very good shape and young, compared to the rest of the population," he said. "A woman at 66, who lies about her age, is usually in good enough shape to convince someone she is 10 years younger."
"We've seen so many compelling stories about how wonderful motherhood is over 50," said Paulson. "It challenges the sexism of our society. It's totally OK to be a first-time dad after 50, but not a mom. A mother has to be young and pretty, but she can't be old."
But from a child's perspective, egg donation can bring its own set of problems, according to David Klimek, an Ann Arbor, Mich., psychologist, who specializes in human development.
"'This is not my biological mother,' a child will think," said Klimek. "'Who was that person, and why is she giving away her eggs, anyway?' It raises a lot of questions."
"During adolescence, even adopted kids go through all kinds of havoc, fighting for their own identity," Klimek said. "They need to know who their parents are. There is a hunger."
Children can also worry if an older parent is sick, fearing that they will die. "Sickness forces a person to become self-absorbed, and they will pull away from the child," Klimek said.
But the choice, he added, should be left up to the individual, and attitudes toward older people have changed.
"We cannot assume anymore that a 55- or 60-year-old is decrepit and dysfunctional with dementia," Klimek said.
Psychologists have compiled data that shows older parents are more compassionate and better able to read the needs of a child, Klimek said. "If you are 30, and frantic, and trying to make a living, the child can be ignored."