In 1978, Louise Brown became first “test tube” baby born anywhere in the world.
British physicians retrieved a single “egg” (pre-ovulatory oocyte) from her mother during her menstrual cycle.They fertilized (added sperm) the egg in vitro (in glass) and then implanted an eight-cell embryo into her uterus. We now know this procedure as in vitro fertilization (IVF).
Less than 10 years later, in 1986 a woman in Australia gave birth after conception with frozen eggs. Two more women gave birth using frozen eggs (1987 and 1988), but other doctors were unable to replicate those results.
Doctors could successfully freeze embryos but not eggs.
In 1989, Dr. Debra Gook had just started working in in vitro fertilization at the Royal Women’s Hospital in Melbourne, Australia, when a close friend received a cancer diagnosis.
“One of the things she regretted was that she could never have a family,” Dr. Gook said. At the time, there was only one fertility-preservation possibility for women who faced sterility from damaging treatments like chemotherapy and radiology: to freeze embryos beforehand.
For single women, that meant a flurry of rushed decision-making. They’d have to choose donor sperm in the short window they had leading up to cancer treatment.
Men, on the other hand, could freeze their sperm easily, an option widely available since the 1970s. “Why is it that she couldn’t have this when it was available to men?” Dr. Gook recalled thinking.
Five years later, in 1994, Dr. Debra Gook cracked the freezing challenge despite having to work around Australian prohibitions on research with embryos. She opened the world’s first egg bank for women with cancer, yet their success rates were low.
Dr. Eleonora Porcu began collaborating with Dr. Gook from Italy. In 1997, her clinic facilitated the first live birth with new freezing methods.
Researchers had solved the fertilization challenge by injecting sperm directly into the an egg. “Ordinarily, sperm cannot penetrate an egg that has been frozen and thawed.”
Two decades after that first IVF birth and concurrent with success in Italy, a woman in Georgia gave birth to twins after her pregnancy resulted from frozen eggs. It was a first for the United States.
In addition to having been frozen, the eggs had been donated from a 29-year-old woman. The 39-year-old mother “had undergone premature menopause and so had no eggs of her own.” She “gave birth to healthy twin boys in August.”
The birth became national news on 17 October 1997. The New York Times reported that Dr. Michael Tucker, an embryologist at Reproductive Biology Associates in Atlanta, would be reporting the results of his efforts at the American Society for Assisted Reproduction.
Men have been able to freeze sperm successfully since the 1970s.
How freezing eggs works
Today, IVF is often a “first line of therapy for all causes of infertility.” According to Penn Medicine, about “1 to 2 percent of all U.S. births annually are via IVF.”
The egg is the largest cell in the human body. It also contains a lot of water; researchers must prevent ice crystal formation when freezing. The procedure uses a flash-freezing process called vitrification.
Recent research suggests that in the long term, freezing eggs may be a more successful option for women who need fertility assistance than traditional IVF.
The optimal age for a woman to freeze eggs is 35 or younger.
A physician uses a process similar to IVF to obtain the eggs, which are stored until a woman is ready to have a child. The procedure benefits women who must undergo chemotherapy, have a hysterectomy or delay childbearing for another reason.
Frozen eggs may yield more successful pregnancies
Research released in 2022 revealed an astounding success rate with frozen eggs. In the study of 543 participants, “70 percent of women who froze eggs when they were younger than 38—and thawed at least 20 eggs at a later date—had a baby.”
- 39 percent of women between 27 and 44 years old, with a majority between 35 and 40 years old at egg freeze, had a least 1 child from their frozen eggs, which is comparable with age-matched IVF outcomes
- women who thawed more than 20 mature eggs had a 58 percent live birth rate, “which was profound and unexpected as this group included people past their reproductive prime.”
- 14 patients who froze eggs at the age of 41 to 43 years successfully gave birth
- How long eggs were frozen did not affect the success rate.
Even though IVF is the more mature technology, the success rate is much lower, possibly because the eggs are older. For women at age 40 who undergo IVF to try to conceive with fresh eggs or embryos, only 30 percent become pregnant and fewer than 20 percent gave birth to live babies.
According to the Centers for Disease Control, 83,946 infants were born in 2019 after being conceived with Assistive Reproductive Technology (ART), which includes both IVF and frozen eggs or embryos.