The Annual Clinic-Specific Report for the Year 1991, issued earlier this year, lists nearly 300 fertility programs in the nation. It includes statistics about each program's success in helping women deliver a baby, using various advanced reproductive techniques. The report is published by the American Fertility Society and the Society for Assisted Reproductive Technology.
Among the centers that did more than 10 in vitro fertilization (IVF) procedures in 1991, the program with the third-highest rate in the country is the South Texas Fertility Center. This program is run jointly by the Health Science Center and Women's and Children's Hospital.
"This report amounts to a national report card for fertility centers," said Kaylen Silverberg, MD, assistant professor of obstetrics and gynecology at the Health Science Center. "Every center's numbers are subject to audit, so this report is the one reliable clinic-specific document that people can use to see what a center is doing."
The report groups patients into different categories by age, and whether male factor infertility (abnormal sperm production) is present. The largest patient category - couples with normal sperm production and the woman younger than 40 - is most often cited in articles about infertility and assisted reproduction.
"Our delivery rate of nearly 35 percent in women under 40 'without male factor' makes us the top-rated center for IVF in Texas and No. 3 in the country, behind two programs in the metropolitan New York area," said Dr. Silverberg. "We did equally well (50 percent) in couples under 40 with male factor." The national rate of success for IVF is 15 percent.
Success has drawn patients. "In 1991 we did 50 procedures," Dr. Silverberg said. "We've already done that many in the first four months of 1993."
He said many of the patients call after reading the clinic- specific report. "Our patients are very sophisticated consumers. They will gladly pay $30 to get this 1,500-page report and they pore through it. As a result, we are seeing more and more patients from outside San Antonio and even outside Texas."
The lab team deserves the bulk of the credit for the San Antonio center's growing national reputation, said Dr. Silverberg. "Our technicians test everything we use in the lab to make sure there are no bacteria, gas residues or infections that could kill the fragile embryos. They pay meticulous attention to quality control."
The laboratory is where eggs, retrieved from the patient, are fertilized in a petri dish with the husband's sperm and incubated for up to 48 hours before being implanted in the woman's uterus. The lab at Women's and Children's Hospital is staffed by Health Science Center technicians.
Current research makes Dr. Silverberg confident the team's IVF success rate will continue. One exciting development is a new application of a technique to evaluate sperm function.
"Until now, if you wanted to evaluate a male for fertility, the only reliable test was a semen analysis," said Dr. Silverberg. "That just tells you how many sperm there are, how many are swimming and what they look like. It doesn't tell you anything about whether they work."
But this new test, called a mannose in vitro binding assay, tells whether the sperm are capable of binding to the shell that surrounds a woman's egg. If the sperm does not bind to the egg's surface, said Dr. Silverberg, it cannot become internalized into the egg and fertilize it.
Information about the assay, which was developed elsewhere and refined in San Antonio by lab technician Tammy Dey, was presented in April in Toronto before the Society for Gynecologic Investigation.
"This test is changing the way we treat patients with male factor infertility," said Dr. Silverberg. Up to 30 percent of infertility cases are due to problems with the man's sperm. In another 20 percent of cases, a sperm problem plays at least a minor role.
"Since we now know in advance that these couples won't do well with IVF, we can change things," he said.
Technicians can inject the sperm directly into the eggs, a technique called micro-manipulation, Dr. Silverberg said. Or they can dissect some of the protective cells away from the egg's surface. A third option is to increase the amount of sperm that they add to the eggs in the petri dish.