By Alison Damast
Staff Writer

STAMFORD — An experimental procedure using frozen eggs has resulted in the first pregnancy of its kind in the state, officials from a local fertility clinic said.A team of doctors at the New England Fertility Institute froze the unfertilized eggs of an anonymous 25-year-old donor for six months, then used one of her thawed eggs to impregnate a 37-year-old woman.
The recipient is in the third month of her pregnancy, which appears to be progressing normally, said Dr. Gad Lavy, medical director and founder of the Stamford-based for-profit treatment center on Summer Street. Doctors would not release the pregnant woman’s identity but said she is a Fairfield County resident.“The reason we were excited about this is we think this is the first pregnancy from frozen eggs in the state,” Lavy said. “Once it is established as a working method, I think a lot of people will embrace it and use it. It has tremendous potential.”

The New England Fertility Institute is one of a number of fertility clinics in the state exploring the use of egg freezing - the scientific term is oocyte cyropreservation - to preserve fertility in aging women.

For a healthy birth, an egg must successfully undergo freezing, defrosting, fertilization, implantation and embryo development.It’s a complicated procedure because eggs have a delicate cell structure that makes them susceptible to damage by ice crystals, Lavy said.

It’s a trend that could change the way young women look at pregnancy, allowing them to push motherhood to an indefinite future date.

Egg freezing is still in its infancy and has produced an estimated 300 babies worldwide, according to a Yale fertility specialist. But no one keeps official statistics. The medical community views it as a highly experimental procedure, said Sean Tipton, an American Society of Reproductive Medicine spokesman.

“There is not a great deal of carefully done published data that indicates that the success rate is yet high enough to say that this is a procedure that should be offered broadly,” Tipton said. “There are many scattered reports of success, but broader replicable studies have been a little tougher to come by.”

Despite the limited success rate, several fertility centers in the state have begun offering clients the option to freeze their eggs, though mostly on a research basis.

The New England Fertility Center began offering egg freezing to patients in the past year and about 10 women have signed up.

Postponing the ticking of the biological clock is just one reason women are interested in keeping their eggs at subzero temperatures, Lavy said.

Couples pursuing in vitro fertilization, or IVF, with ethical concerns about excess embryos are expressing interest in the technology. Egg freezing also is an option for women undergoing radiation or chemotherapy who are concerned about potential damage to their ovaries.

It can cost upward of $8,500 for freezing eggs and later thawing them and using conventional IVF methods. Patients have not been charged for egg freezing because it is such a new procedure, Lavy said.

The center began experimenting with thawing frozen eggs over the past three years, using eggs from donors. They recently thawed three eggs, one of which was implanted in the woman who is now pregnant.

“It’s very difficult to get immediate results. This is why we turned to the donor eggs, which we can turn around quickly,” Lavy said. “You have to show that you have successful pregnancies.”

The center uses the slow freezing method, a procedure perfected by scientists in Italy who learned to freeze unfertilized eggs after the government banned freezing embryos.

A woman who wants to freeze her eggs must take drugs to produce multiple eggs, as is typical in IVF, Lavy said.

After the eggs are removed from a woman’s ovaries, a lab technician places them in a machine called the Kyro 10, which lowers the temperature of the eggs in stages.

The eggs are then frozen in cryogenic tanks the size of a large washing machine, where they are stored in stacked vials.

The tank is submerged in liquid nitrogen, which keeps the eggs at minus 196 degrees Celsius, a temperature that preserves the egg and prevents cell damage.

Water in the cell turns into ice during the freezing process and can eventually cause a portion of the egg to swell or rupture.

Fertility centers now use cryoprotectants, which act like antifreeze, to protect the egg during freezing and thawing.

Despite these advents, the chances of becoming pregnant from a frozen egg are slim.

A recent study that compared the outcome of IVF with frozen eggs versus unfrozen eggs showed a low success rate using frozen eggs, according to an article published in the July issue of Fertility and Sterility, a medical journal.

The chance of one sperm-injected egg becoming a live infant was 6.6 percent using unfrozen eggs, and 3.4 percent with frozen eggs, the study showed.

Those statistics can be disheartening to women who believe they put motherhood on hold by freezing their eggs, said Dr. Claudio Benadiva, director of the IVF lab at the University of Connecticut Health Center’s Center for Advanced Reproductive Services.

“If you are going to tell patients that this is a standard of care or that it is ready for prime time, it is a little bit misleading because it is not,” Benadiva said.

UConn doctors take a cautious approach to egg freezing and began offering it this fall to a limited number of patients through a study, Benadiva said.

Only couples undergoing IVF who don’t want to freeze additional embryos for ethical or religious reasons can participate in the study, which has not resulted in any pregnancies, Benadiva said. These patients are not charged fees for egg freezing.

“Until we have some success and some results, we don’t want to offer this to patients because it is not fair,” he said. “The people who want to freeze their eggs are not going to use them for several years and we don’t want to make them think they have their fertility guaranteed.”

Doctors at the Yale Fertility Center have taken a similar approach. They have frozen about 28 eggs since the center began offering the service last year, said Dr. Pasquale Patrizio, director of the fertility center. Patients are not charged for freezing the eggs, though they pay for egg retrieval, monitoring and storage after the first year.

About 20 of Yale’s frozen eggs have come from women who have breast cancer, but most of the remaining ones have come from women holding off on motherhood, Patrizio said. No live births have resulted because nobody has requested to thaw their eggs for IVF, he said.

A 40-year-old graduate student who wanted to remain anonymous said she is freezing her eggs at the Yale Fertility Center. She and her husband have been married about a year, but are not ready to have children and have moral objections to freezing embryos, she said.

“There are things in our personal lives that are preventing us from having children right now, so it just felt a little bit less ethically messy,” she said. “It almost feels like I’m kind of getting a chance to preserve my youth a little bit, too.”

Patrizio said he believes egg freezing will become an accepted practice as doctors continue to document healthy births and refine the procedure.

“My guess is that in the next six months, as the number of births reported worldwide increases, it will put the technology into the mainstream of treatments available,” he said. “Therefore, we will lose this kind of experimental label it has now.”

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