The latest medical technology lets women get pregnant after menopause, but also raises questions about how old is too old for child-rearing. Doctors say they can extend women's baby-making years well into their 40s, 50s and perhaps 60s, providing a second chance for those who waited too long to start families. However, some doctors have doubts about the wisdom of childbearing for those who are well past nature's own cutoff.
"Because we can do something technically does not mean we should do it indiscriminately," said Dr. Zev Rosenwaks. "The ability to become pregnant is a physical sign of what nature itself expects of a woman. You cannot push nature past the point where you interfere with safety."
Rosenwaks is head of the fertility clinic at New York Hospital-Cornell Medical Center, one of several hospitals around the country that has begun using the new technology.
Pregnancy is riskier for older women than young ones. They are more likely to have high blood pressure, premature labor and bleeding. Doctors note that there is simply no way to know the effects of carrying and delivering a child on a women in her 50s and beyond.
"We don't have any data on that. It opens up a Pandora's box," said Dr. Steven Bayer of New England Medical Center.
Others noted that older women should carefully think about whether they have the stamina to deal with 2 a.m. feedings and other rigors of bringing up babies.
(For the record, the oldest mother to give birth without the new technology was Ruth Alice Kistler of Portland, Ore. According to the Guinness Book of World Records, her baby was born on Oct. 18, 1956, when Kistler was 57 years old. Kistler died in 1982.)
The new process, described in Thursday's New England Journal of Medicine, is a variation on the now-routine process of in vitro fertilization, conception in the lab dish. Ordinarily, doctors remove eggs from an infertile woman's ovaries, mix them with sperm and then put the embryos into her womb.
However, this is not possible if the woman's ovaries have stopped working, the change of life known as menopause. Until recently, that was the end of the reproductive line for women.
But now, doctors are removing eggs from healthy young donors and implanting them in older women after they have been fertilized with sperm. Because the mother does not provide the egg, she is not the genetic parent of her baby, but still undergoes a normal pregnancy and delivery.
The major limits to the technique are the health of the mother and the cost _ $8,000 for each attempt plus a $1,500 payment to the egg donor.
In the journal, Dr. Mark Sauer of the University of Southern California described the use of the technique on seven women over 40 whose "ovaries didn't last as long as their desire to have babies."
Menopause usually occurs around age 50, but in about 10 percent of women the ovaries stop working by age 40.
"Many women are coming in 40 years of age or older. They have an air of desperation. It's their last chance," said Dr. Anne Wentz, who has an infertility practice at Northwestern University.
"There is concern about progressively older individuals trying to provide parenting for an infant and a child as it grows up," said Dr. Machelle Seibel of Faulkner Hospital in Boston. "I have no right to say what is the right age, but at some point there has to be limits to what age is appropriate."
Dr. Kamren Moghissi of Wayne State University added: "Some of them won't live to see their kids get married or even graduate from college. The natural lifespan for women is around 80 years, but some women die at age 60 or 65. These women obviously won't see their children grow up."