Egg freezing producing more births than when fresh eggs used, study finds

November 6th, 2012 in Obstetrics & gynaecology /

Advances in egg freezing techniques are producing pregnancy rates and healthy babies comparable to the rates seen with in vitro fertilization (IVF) using fresh eggs, according to a recent report by the American Society for Reproductive Medicine (ASRM). The report also removed the word "experimental" when talking about egg freezing and officially sanctioned the techniques as viable and proven options for young women whose medical treatments may endanger their fertility.

The Center for Advanced Reproductive Services (CARS) at the University of Connecticut Health Center is one of a select few IVF centers in the area which has successfully used and found positive results. The Center completed a clinical study in 2011 that evaluated the efficacy of egg freezing in patients undergoing IVF. Egg freezing is a relatively new technology that allows patients the option of storing frozen eggs instead of , eliminating some of the ethical and religious concerns that accompany embryo freezing, storage and disposal.

The research was conducted by Dr. Claudio Benadiva, director of the IVF laboratory at CARS, and Linda Siano, chief embryologist, and evaluated a method of rapid freezing of eggs called vitrification. According to Benadiva, "We have found this technology has the potential to revolutionize the field of reproductive medicine, offering a clinically viable alternative to women seeking to preserve fertility for medical reasons, or who are of reproductive age but simply not ready to start a family."

Patients who volunteered to participate in the study had a portion of their eggs frozen during a process in which eggs are retrieved from a woman's ovaries, frozen in a cryoprotective solution and then thawed. The thawed eggs were then warmed and fertilized with their 's through a process called intracytoplasmic sperm injection (ICSI), and used to obtain a pregnancy.

The study found positive results. Data demonstrated a clinical pregnancy rate of 53.8 percent and a live birth/ongoing pregnancy rate of 46.1 percent. So far, seven babies (one set of twins) have been born from frozen to patients who participated in the study. "The results from this study show promise and are very encouraging," says Siano. "We will continue to analyze the data and refine our technique to provide patients with the absolute best chance for success."

Until now, egg freezing was considered experimental by ASRM. This is in part due to the fact that many centers around the country offering egg freezing had a very low success rate regarding pregnancy. According to Benadiva, "We are pleased to be one of the few IVF Centers offering egg freezing and we are doing so after having demonstrated measureable success in our approved clinical trials. Our proven success is now supported by the ASRM and we hope that opens the door further and results in more healthy pregnancies," adds Benadiva. By removing the "experimental" classification, the hope is that insurance companies may begin to pay for egg preservation for young women who face treatments that can reduce their future fertility, such as chemotherapy for cancer.

According to the most recent data, it is estimated that close to 2,000 births have occurred worldwide from egg freezing with about 1,000 from the past five years.

More information: www.uconnfertility.com/

Provided by University of Connecticut

"Egg freezing producing more births than when fresh eggs used, study finds." November 6th, 2012. http://medicalxpress.com/news/2012-11-egg-births-fresh-eggs.html