What's the Difference between Donor Eggs and Donor Embryo?

I must admit that it is kind of confusing to understand all the terminology and different kinds of treatment options that are available for infertility. So, I'm going to attempt at clarifying two often mis-understood terms. Many people think they are the same, but actually they are quite different.

Donor Eggs: Our infertility specialist recommended that we use donor eggs due to my poor ovarian reserve. Many infertile women are unable to conceive because their eggs are of poor quality (often due to age), but other times due to factors unknown. The only way that some infertile women could conceive is by finding someone who will donate her eggs. Often, the donors tend to be younger women, in their 20's or early 30's, who out of altruistic reasons or for extra income, donate their eggs to the infertile couple. It is physically demanding process for the donor because she must go through the hormone injections and monitoring in order to produce as many eggs as possible for the infertile woman. The eggs are then retrieved from the donor, fertilized with the sperm of the husband of the infertile woman (or a sperm donor). Once the eggs have been fertilized, then the embryos are transferred back into the infertile woman hoping for successful pregnancy.

When I was in Bombay, there was a couple who had brought their own egg donor all the way from Vietnam. The infertile woman was 45 years old (Vietnames), but the egg donor was only in her mid 20's. So by using another woman's eggs and her husband's sperm, they created several embryos. A couple of the embryos were transferred back to the 45 year old infertile woman and I heard that she was pregnant. They have a few frozen embryos in the clinic in case they want to try to get pregnant again at a later point.

Donor Embryo: As mentioned above, there are many frozen embryos in clinics throughout the U.S. and in other countries. Usually, a couple has the choice of either freezing the remaining embryos for future use, discarding them, or giving them up for research. Many choose to freeze. After some time, some may decide that their family is complete but they still have a few frozen embryos left in the clinic. They must decide on the fate of these extra embryos.

This is where embryo donation/adoption comes in. Rather than destroying these frozen embryos or giving them up for research, some may choose to donate their embryos to other infertile couples. This then gives the embryos a chance at life and infertile couples a chance at becoming parents. The frozen embryos are thawed and then put back into the infertile woman. At this point, the hope is that the embryos would continue to grow and implant inside the infertile woman resulting in live birth.

I don't know whether I have managed to clarify the difference between the two or whether I have created even more confusion.... Donor eggs have been around for some time, but the embryo adoption (embryo donation) is less common. However, I believe it is becoming more common. Paul and I are currently exploring embryo adoption, not donor eggs.