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As reported by The Hartford Courant, March 27, 2011.

Freezing Eggs: UConn Offers Women Another Option

Six Babies Born Through New Colder-Temperature Technology

By William Weir

Joni Stehlik and her fellow researchers were searching for a way to improve the success rate of fertilizing women's eggs after freezing and thawing them out.

They had tried one variation after another to no avail. One suggestion was to freeze the eggs at a faster rate and at much colder temperatures than the standard method. After all the other attempts, Stehlik didn't hold out much hope for this new twist.

"I thought it was B.S,," she said. "I never thought it was going to work."

Not only did it work, it turned out to be one of the breakthroughs in the science of egg-freezing, a procedure in which eggs are removed from a woman's body and frozen in liquid nitrogen. They're stored until the woman is ready to have a child, at which time they're thawed, fertilized and re-implanted.

Stehlik was working at the Advanced Institute of Fertility in Milwaukee when they made the discovery. She since has brought the procedure, known as vitrification, to the University of Connecticut Health Center in Farmington, where she is the operational laboratory director at the Center for Advanced Reproductive Services.

A clinical study of the procedure, which is still considered experimental, at the health center has resulted in the births of six babies through the procedure, the first of them in August last year. And in July, UConn's Center for Advanced Reproductive Services will begin offering this option for prospective mothers.

The procedure allows women who have a medical condition that could affect their fertility, such as cancer, to save their eggs while they're healthy, for fertilization later. It also can serve the needs of women who are getting older but would prefer to have children later. When it comes to fertility, it's not the woman's age that matters, but the age of her eggs.

When frozen correctly, Stehlik said, the eggs can remain healthy indefinitely.

Internationally, there have been more than 900 births through egg-freezing, two-thirds of them in the past three years.

The women who took part in the study initially came to the center for traditional fertility treatment, but volunteered for the study in exchange for a free cycle of in-vitro fertilization (IVF). About 16 eggs were removed from each woman, half of which were frozen and then thawed. They then were fertilized by intracytoplasmic sperm injection, in which a sperm is injected into the egg. In case this procedure didn't work, the other half of the eggs were fertilized without freezing and thawing.

The study, led by the center's IVF laboratory director, Claudio Benediva, and chief embryologist, Linda Siano, was for research purposes only. The women who took part all entered the study with their partners, and they weren't in a health situation that required them to freeze their eggs for later. The UConn researchers say the procedure had a success rate of 46 percent, compared to its 55 percent success rate for traditional IVF treatment. Encouraged by these numbers, health center officials decided to offer the option to prospective mothers.

How the success rate compares to other studies in the U.S. is difficult to say. Unlike traditional IVF treatments, results of egg-freezing cycles aren't required to be reported to the U.S. Centers for Disease Control and Prevention. Dr. Andrew LaBarbera, scientific director of the American Society of Reproductive Medicine (ASRM), said there is no standardized procedure for how researchers compile the results of their egg-freezing studies.

The ASRM categorizes egg-freezing as experimental, and women who go through the program at UConn will be informed of this, said Dr. John C. Nulsen, director and a lead physician at the Center for Advanced Reproductive Services.

The experimental status also requires an institutional review board to monitor the program. It additionally means that insurance companies rarely cover the costs of the procedure, which usually range from $10,000 to $12,000.

The experimental status of freezing eggs has been a matter of debate in the reproductive science field. An article last year in the Journal of Assisted Reproduction and Genetics argued for lifting the experimental status. Authors Nicole Noyes of the NYU Fertility Center, Jeffrey Boldt of Assisted Fertility Services at Community Health Network Inc. in Indianapolis, and Zsolt Peter Nagy of Reproductive Biology Associates in Atlanta noted that babies born as a result of egg-freezing have had the same average birth weights and no more congenital anomalies than other babies.

But LaBarbera said there's still not enough information to know the safety and efficacy of the procedure. For one thing, he said, there needs to be a larger population of children born through the process to allow researchers to collect enough data to accurately gauge what the health risks are.

"We encourage further research in this area, but we feel that patients need to know that it is experimental," he said.

Nulsen credits UConn's success with egg-freezing largely to the vitrification process that Stehlik helped refine. It involves a rapid cooling process that takes five to 10 minutes, in which the eggs are frozen and dehydrated. The eggs are then stored in liquid nitrogen at 196 degrees Celsius below zero. Faster freezing, Stehlik explained, reduces the possibility of ice crystals forming, which can damage the egg. It's a delicate procedure that requires absolute precision, said Stehlik even very slight variations can hamper the process.

Although Nulsen said the process avoids many of the ethical concerns that some people have about freezing human embryos, the emerging technology has raised new ethical concerns. Some in the field say egg-freezing could cause healthy women in their 20s and 30s to put too much faith in a still-developing science and delay having children until later.

Cheryl Ball said she knew the risks of egg-freezing when she decided it was her best option. A few years ago when she was single and in her mid-30s, Ball said she was worried about her chances of having children. After discussing her options with doctors and friends, it was through a Google search that she stumbled on the possibility of egg-freezing, something she had never heard of before.

"I wasn't with the person I was going to have children with, and I realized my biological clock was ticking," she said. "I didn't want to go through [a pregnancy] as a single mother. I just thought it seemed like a good alternative."

In 2006 when she was 37, Ball, who lives in North Attleboro, Mass., had her eggs frozen at Extend Fertility, a clinic in Boston. She hasn't had eggs thawed yet, and isn't sure when she will. She's glad she did it.

"The only risk was a financial one; there's no guarantee that the procedure is going to work," she said. "I didn't want to feel pressured into a relationship that wasn't quite right for me."