Studies find frozen eggs as good as fresh for IVF—almost 90 percent thawed successfully—dispel doubts about vitrification process
SEATTLE, January 21, 2010 — Fertility specialists responsible for the first pregnancy in the Pacific Northwest resulting from frozen human eggs are hailing new research showing that frozen eggs can be as effective as fresh eggs in helping previously infertile women achieve pregnancy.
Among the new studies presented at the annual meeting of the American Society for Reproductive Medicine in October was one from Reproductive Biology Associates of Atlanta, finding that 85 percent of eggs survived thawing and that subsequent in vitro fertilization (IVF) of those eggs generated a 67-percent pregnancy rate—as good as the average success rate for fresh eggs. A second study from the New York University Fertility Center reported similar results in women who used frozen eggs to preserve fertility after cancer treatment. “Until recently, egg freezing was largely reserved for women undergoing cancer treatment who set aside their eggs in hopes of preserving post-recovery fertility options,” said Dr. Gerard Letterie of the Northwest Center for Reproductive Science (NCRS).
Letterie’s long-time research interests have included fertility preservation in cancer patients and as an elective option in patients who want to preserve fertility for non-medical reasons. The option was almost non-existent before 2004, and today NCRS is one of a small minority of fertility practices capable of egg freezing, thawing and fertilization.
Letterie said there has been ongoing debate in the medical community about the use of egg freezing to delay childbearing because traditional egg freezing, or cryopreservation, often forms crystals on eggs during the freezing process, making them less viable. “These new studies further reinforce our successful experiences with vitrification, a fast-freezing process that protects eggs much better than traditional cryopreservation,” he said.
“When eggs can be frozen and thawed successfully, we can create fewer embryos on an as-needed basis, going back to storage for more later rather than putting a patient through the time, expense and physical and emotional strain of additional egg retrievals,” he said.
Improved egg freezing technology allows NCRS to help women postpone pregnancy for a variety of personal reasons, whether due to medical necessity, career demands, lack of a partner, or religious and spiritual dilemmas.
“It is becoming increasingly common for single women who feel the pressure to find a perfect partner by their mid-30s, and haven’t, to elect this option. Freezing their eggs guarantees them a chance of having their own biological children that they may not have if it took them another five years to find their desired partner, or in some cases, begin their families as single mothers by choice,” he added.
