Success rate elusive on frozen eggs - The chances of bringing home a baby after harvesting and preserving a woman's eggs remain unknown. Often eggs are never retrieved.
Freezing eggs for non-medical reasons — in which a healthy woman harvests and preserves her eggs for later conception — is new enough that there are few reliable statistics on the success of the procedure. "Success" in such cases means a take-home baby, not just an egg that is frozen without damage, or thawed safely or even fertilized to yield a genetically normal, healthy embryo.
"So few women who have frozen eggs have come back to use them [that it's impossible] to quote a clear pregnancy rate on it," says Dr. Elizabeth Ginsburg, medical director of assisted reproductive technologies at Brigham and Women's Hospital. Because women usually plan to freeze eggs for many months or years before retrieving them for conception, there simply hasn't been time to collect enough data.
But the idea is clearly catching on. Nationwide, roughly half of 282 U.S. fertility centers surveyed offer egg freezing, according to a USC study published in the June issue of Fertility and Sterility, a journal of the American Society for Reproductive Medicine. About 400 fertility centers are currently operating in the U.S.
A woman who decides on egg freezing is first given hormones to stimulate egg production. At Boston IVF, the eggs are then retrieved while the woman is under general anesthesia; other centers may use IV sedation plus painkilling drugs.
The process, not usually covered by insurance, can cost $10,000 or more per procedure. Beyond the initial expense, there are annual fees, often hundreds of dollars, to maintain the eggs.
At Boston IVF, a leading fertility center in the U.S. and one of the oldest as well, typical fees are $6,000 for the harvesting and freezing of eggs; that doesn't even cover the cost of hormones and medications, subsequent fertilization or transfer of eggs to the uterus.
The center has begun offering seminars on the process to young women, many of who are just out of college or graduate school and heading into the work force.
No guarantees
Traditionally, egg freezing "has been used in women with cancer who face imminent loss of ovarian function. But recently, the technology has advanced to the point where it is worth using for women who want to preserve their oocytes for social reasons," says Dr. Briana Rudick, a reproductive endocrinologist at USC and the lead author of the survey.
Two-thirds of the clinics in the USC survey reported that they made the service available to women for such elective reasons.
There are no reliable numbers for how many women have chosen to have their eggs frozen. About 60 women have done so at Boston IVF, most of them as a hedge against advancing age, says Dr. Kim Thornton, clinical director of the center's egg-freezing program. So far none has returned for the next step, she said.
Worldwide, more than 900 babies have been born from frozen eggs, according to a 2009 study conducted by researchers at the New York University Fertility Center and published last year in Reproductive BioMedicine Online.
Of course, there are no guarantees that freezing eggs will preserve fertility, just as there are no guarantees — at any age — that a woman can get pregnant naturally. In both cases, the odds get worse as egg quality declines with age.
"Humans are the poorest of all mammalian species in terms of chromosomal integrity," says Dr. Geoffrey Sher, founder of the Sher Institutes for Reproductive Medicine in Las Vegas, N.M. "With humans, even when they're young, there's only a 2 in 5 chance that an egg is normal. By the time a woman is 45, approximately 1 in 15 is normal."
"Pregnancy rates at age 40 are pretty low even with fresh eggs," says Ginsburg at Brigham and Women's. "You can chop that by two-thirds if it's frozen eggs."
A young field
The first pregnancy that resulted from a frozen egg occurred in 1986, and two major professional groups, the American College of Obstetricians and Gynecologists and the American Society for Reproductive Medicine, still consider egg freezing experimental. In fact, they caution that a request to freeze eggs should be reviewed by an institutional review board before being granted.
Still, several advances are nudging the use of egg-freezing forward. One is "vitrification," in which eggs are frozen within 15 minutes. Typically, eggs have been frozen slowly, over several hours, using programmable freezers that drop temperatures step by step. While many fertility clinics still use this method, it allows for the creation of ice crystals, making egg survival only about 60%, says Michael Tucker, scientific director at Georgia Reproductive Specialists in Atlanta. The claim with vitrification is that the egg survival rate may rise to 80% or even higher.
Testing the genetic viability of both eggs and embryos has also boosted interest in freezing. Several methods are available, including comparative genomic hybridization (CGH), which checks eggs or embryos to be sure they have the correct number of chromosomes. Some embryos appear normal under the microscope but have the wrong number of chromosomes, meaning they are not viable, Sher says.
Bottom line, a woman who wants to conceive a child at some point in the future should carefully consider the options — the risks, costs and unknowns.
Regarding the use of egg freezing, a more recently available choice, Ginsburg advises, "If you want to have a child and it's feasible socially, do it. ... I get infertile patients, married for five years, who couldn't imagine having a baby in [their] small apartment. That's a bad reason to wait until age 35. It's really sad, and I see it a lot." (latimes.com )
Freezing eggs for non-medical reasons — in which a healthy woman harvests and preserves her eggs for later conception — is new enough that there are few reliable statistics on the success of the procedure. "Success" in such cases means a take-home baby, not just an egg that is frozen without damage, or thawed safely or even fertilized to yield a genetically normal, healthy embryo.
"So few women who have frozen eggs have come back to use them [that it's impossible] to quote a clear pregnancy rate on it," says Dr. Elizabeth Ginsburg, medical director of assisted reproductive technologies at Brigham and Women's Hospital. Because women usually plan to freeze eggs for many months or years before retrieving them for conception, there simply hasn't been time to collect enough data.
But the idea is clearly catching on. Nationwide, roughly half of 282 U.S. fertility centers surveyed offer egg freezing, according to a USC study published in the June issue of Fertility and Sterility, a journal of the American Society for Reproductive Medicine. About 400 fertility centers are currently operating in the U.S.
A woman who decides on egg freezing is first given hormones to stimulate egg production. At Boston IVF, the eggs are then retrieved while the woman is under general anesthesia; other centers may use IV sedation plus painkilling drugs.
The process, not usually covered by insurance, can cost $10,000 or more per procedure. Beyond the initial expense, there are annual fees, often hundreds of dollars, to maintain the eggs.
At Boston IVF, a leading fertility center in the U.S. and one of the oldest as well, typical fees are $6,000 for the harvesting and freezing of eggs; that doesn't even cover the cost of hormones and medications, subsequent fertilization or transfer of eggs to the uterus.
The center has begun offering seminars on the process to young women, many of who are just out of college or graduate school and heading into the work force.
No guarantees
Traditionally, egg freezing "has been used in women with cancer who face imminent loss of ovarian function. But recently, the technology has advanced to the point where it is worth using for women who want to preserve their oocytes for social reasons," says Dr. Briana Rudick, a reproductive endocrinologist at USC and the lead author of the survey.
Two-thirds of the clinics in the USC survey reported that they made the service available to women for such elective reasons.
There are no reliable numbers for how many women have chosen to have their eggs frozen. About 60 women have done so at Boston IVF, most of them as a hedge against advancing age, says Dr. Kim Thornton, clinical director of the center's egg-freezing program. So far none has returned for the next step, she said.
Worldwide, more than 900 babies have been born from frozen eggs, according to a 2009 study conducted by researchers at the New York University Fertility Center and published last year in Reproductive BioMedicine Online.
Of course, there are no guarantees that freezing eggs will preserve fertility, just as there are no guarantees — at any age — that a woman can get pregnant naturally. In both cases, the odds get worse as egg quality declines with age.
"Humans are the poorest of all mammalian species in terms of chromosomal integrity," says Dr. Geoffrey Sher, founder of the Sher Institutes for Reproductive Medicine in Las Vegas, N.M. "With humans, even when they're young, there's only a 2 in 5 chance that an egg is normal. By the time a woman is 45, approximately 1 in 15 is normal."
"Pregnancy rates at age 40 are pretty low even with fresh eggs," says Ginsburg at Brigham and Women's. "You can chop that by two-thirds if it's frozen eggs."
A young field
The first pregnancy that resulted from a frozen egg occurred in 1986, and two major professional groups, the American College of Obstetricians and Gynecologists and the American Society for Reproductive Medicine, still consider egg freezing experimental. In fact, they caution that a request to freeze eggs should be reviewed by an institutional review board before being granted.
Still, several advances are nudging the use of egg-freezing forward. One is "vitrification," in which eggs are frozen within 15 minutes. Typically, eggs have been frozen slowly, over several hours, using programmable freezers that drop temperatures step by step. While many fertility clinics still use this method, it allows for the creation of ice crystals, making egg survival only about 60%, says Michael Tucker, scientific director at Georgia Reproductive Specialists in Atlanta. The claim with vitrification is that the egg survival rate may rise to 80% or even higher.
Testing the genetic viability of both eggs and embryos has also boosted interest in freezing. Several methods are available, including comparative genomic hybridization (CGH), which checks eggs or embryos to be sure they have the correct number of chromosomes. Some embryos appear normal under the microscope but have the wrong number of chromosomes, meaning they are not viable, Sher says.
Bottom line, a woman who wants to conceive a child at some point in the future should carefully consider the options — the risks, costs and unknowns.
Regarding the use of egg freezing, a more recently available choice, Ginsburg advises, "If you want to have a child and it's feasible socially, do it. ... I get infertile patients, married for five years, who couldn't imagine having a baby in [their] small apartment. That's a bad reason to wait until age 35. It's really sad, and I see it a lot." (latimes.com )
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