These days, most of Dr. Mark V. Sauer's patients are past their reproductive primes.
In the past five years, about 200 women in their 40s and 50s have attempted to get pregnant via donor eggs at the USC-IVF Program.
About 75% of those midlife patients are trying for their first child, Sauer says.
He is straightforward about their chances. Infertile older women get pregnant at the same rates as infertile younger women. "Approximately one of three women will carry a baby home every time they attempt it," Sauer says.
"If they stay with the program (if initial attempts fail), more than 50% will achieve a pregnancy that will result in the birth of a child. If they are willing to do it eight or nine times, they have a 90% chance of having a child."
Sauer's figures jibe with national averages compiled by the American Society for Reproductive Medicine, says Joyce Zeitz, a spokeswoman for the Birmingham, Ala.-based organization.
In 1992, the most recent year for which statistics are available, egg donation resulted in an overall pregnancy rate of 36% per attempt regardless of age, she says, with a 31% delivery rate.
There is no separate data for midlife patients.
Before entering the USC-IVF Program, older women must undergo rigorous medical screening, including a treadmill stress test, mammogram, blood tests and chest X-ray.
Diabetes, cardiovascular conditions and other health problems must be ruled out.
Once the patient passes, she is matched anonymously with a donor--unless a friend or relative agrees to play that role.
Next, the recipient is synchronized via hormone treatments with the donor's menstrual cycle.
Meanwhile, the donor injects herself with hormones that prompt multiple eggs--the more the better--to mature.
When the eggs are ripe, they are retrieved and taken to the lab for fertilization.
Finally, the embryo is transferred to the recipient, who takes hormones to support the pregnancy.
A pregnancy test is performed nine days later.