Delayed Embryo Transfer Suggested for At-Risk Women
Method may protect ovaries from hyperstimulation in in-vitro fertilizations
WEDNESDAY, Oct. 25, 2006 (HealthDay News) -- Delaying embryo transfer in certain high-risk women who have in-vitro fertilization (IVF) helps protect the woman's health and improves the chances that she'll have a baby, say Mayo Clinic researchers.
They found that this method is effective in women at risk for potentially life-threatening ovarian hyperstimulation syndrome, in which the ovaries become highly sensitive to hormonal changes and start to enlarge -- sometimes to the size of an orange or grapefruit.
This condition occurs in about 5 percent of women treated with medications to prompt ovulation -- the first step in the IVF process.
In women at risk for this syndrome, embryo transfer into the uterus should be delayed after the woman's eggs have been fertilized in the laboratory. All the embryos should be frozen until the woman's risk for ovarian hyperstimulation syndrome subsides naturally with time, the Mayo researchers said.
"We take steps to minimize ovarian hyperstimulation syndrome as an issue. If we feel that there's a good chance a woman would get this syndrome, then we would recommend complete cryopreservation -- freezing -- of her embryos and waiting about a month or so to complete the embryo transfer," senior study researcher Dr. Charles Coddington, a reproductive endocrinologist, said in a prepared statement.
The study included 188 women at risk for ovarian hyperstimulation syndrome who were treated using three different strategies, including delayed embryo transfer.
"We conclude that elective embryo cryopreservation with subsequent embryo transfer is an effective way of preventing severe ovarian hyperstimulation syndrome and its life-threatening consequences," Coddington said. "The quality and pregnancy potential of the frozen embryos remains excellent, as demonstrated by the high cumulative live birth rate per patient."
The findings were to have been presented Tuesday at a meeting of the American Society for Reproductive Medicine in New Orleans.
The U.S. National Women's Health Information Center has more about infertility.