Science is allowing older women such as Mary Shearing to fulfill their desire for motherhood _ the 53-year-old grandmother is pregnant with twins.
But some experts are questioning the cost to their children and society.
"Mentally, people can stay up, but physically, even with the strides in medicine, I'm not so sure we're not cheating the children," said Ruth Wetherby, manager of social services for Western Medical Center in Santa Ana.
"By the time the child is a teenager, you're not going to be a mom in her 30s, bouncing around," she said.
Dr. Arthur Caplan, director of the Center for Biomedical Ethics at the University of Minnesota, said the impact on children is difficult to assess.
Older parents will be less energetic, and children may find themselves caring for aged parents early in life, he said.
"I'm not sure it's a reason not to have kids, but it's an additional burden, so parents ought to provide for it," Caplan said.
Mrs. Shearing and her 32-year-old husband, Don, of Orange, say they have considered the potential pitfalls _ and found them outweighed by the benefits.
"Having a baby is just an incredible experience _ bringing a life into the world," said Mrs. Shearing, mother of three grown children from a previous marriage and a grandmother.
Although she was going through menopause, she was given embryos created from donated eggs and her husband's sperm. Her twins are due in December.
"The age consideration, while it's important, is not something you run your life by," she said. The couple said they went public, in part, as a reaction to negative comments they heard about menopausal pregnancies.
A recent study found that women over age 40 are just as successful at bearing healthy babies with donated eggs as younger women, as long as the eggs come from a younger donor.
The study, in the Sept. 9 Journal of the American Medical Association, found the standard in-vitro or test tube fertilization technique offered to most infertile older women works much better with donated eggs from women under age 35 than with the older woman's own eggs.