Since the first IVF baby was born in 1978, fertility treatments have grown at an exponential rate. Thanks to these medical advancements, an increasing number of couples are finally getting to realize their dream of having a family.
Frozen donor eggs are one of the paths giving hope to many today.
So, what’s involved in using frozen donor eggs, how has it advanced, and what are the success rates?
We find out below.
In-vitro fertilization (IVF) has revolutionized the treatment of infertility. Image credit: Pixabay, free license
Who Can Be an Egg Donor?
The majority of egg donors choose to donate their eggs because they want to help others start a family. However, there are some specific criteria that an egg donor must meet.
While ages may vary by clinic or egg bank, first-time donors are often aged between 21 and 28 years old. Sometimes, women may donate up until the age of around 33 if previous egg donations have been successful.
Egg donors are also asked to undertake a number of evaluations, including drug tests, medical history, and psychological assessments. Again, the required screening carried out may vary carried out may vary by clinic, but ensuring an egg donor is in good overall health is imperative for the health of the donor, recipient, and baby.
What’s Involved in Receiving Frozen Donor Eggs?
After a donor is approved, they start a cycle of medications that help stimulate a number of mature oocytes (ovary cells–or eggs) to develop. These eggs are retrieved directly from the ovaries under light anesthesia.
Once retrieved, they are frozen. In the United States, in the US oocytes can be stored indefinitely. In fact, the oldest known case of a successful live birth after using frozen eggs is 30 years!
While 30 years is an extreme, the eggs from donors are frozen until they are selected by a recipient. Recipients are often given access to a clinic’s or egg bank’s database of donors so they can carefully select someone. This choice may be governed by the overall characteristics of the donor or by something specific, such as the eye color or race of the donor.
After choosing the ideal donor, the recipient then undergoes a course of estrogen then progesterone to ensure their uterus is ready for implantation. Then, the eggs are thawed before being fertilized with the partner’s or a donor’s sperm. The embryos created from this process are placed into incubation and are typically transferred to the recipient three to five days following fertilization. The process may differ slightly if the embryos are being created and frozen for a future embryo transfer.
Approximately two weeks later, the recipient takes a pregnancy test.
What Are the Success Rates with Frozen Donor Eggs?
The latest data from the CDC (data collected in 2020) suggests that there was a 47.4 percent success rate (live-birth delivery) when using frozen eggs in an assisted reproductive technology (ART) cycle. When using fresh donor eggs, this was only slightly higher at 54.7 percent.
These figures highlight the narrowing gap between the success rates of fresh and frozen donor egg. For example, ten years prior, in 2010, the success rate for frozen donor eggs was 34.9 percent compared to 55.8 percent in fresh donor egg. In 2015, it was 42.3 percent versus 55.6 percent (frozen vs. fresh respectively).
This success is largely due to the advancements in the freezing method. Previously, a slower method was used which often led to the formation of ice crystals in the egg. This, in turn, could damage the structure of the egg. Now, the latest egg-freezing (or vitrification) technology available helps to minimize the formation of ice crystals, therefore increasing the chances of success.
Vitrification is often referred to as ‘fast freezing’ and works by exposing the oocytes to a cryoprotectant solution and then placing them in liquid nitrogen. Then, the eggs are placed in liquid nitrogen. The freezing process is extremely rapid and helps preserve the eggs during the freezing process, while also aiming to prevent as much degradation during the thawing and fertilization processes.
The Future of Assisted Reproductive Technology
As you can see, since the first IVF baby was born 35 years ago, ART has advanced in leaps and bounds. And, with new technological advancements each and every day, there is no telling where we will be in the next 35 years. Thanks to the progress that has already been made, however, many couples now have the convenient choice of frozen donor egg.