Freezing eggs and freezing embryos are two separate processes, each with their own advantages and disadvantages. In the past, when slow freezing technology was used to freeze eggs and embryos, frozen embryos had the higher survival rate. Now, due to the process of vitrification, the survival rate of an embryo and an egg is almost the same.
However, many individuals still believe that the chances of a frozen embryo resulting in a pregnancy are still higher. But when you look at the statistics, it’s not a true comparison. Regardless of the method you choose, you still need several eggs to get one embryo. You may choose to first freeze your eggs and then fertilize them later to form embryos. You can also use fresh eggs, fertilize them and freeze the resulting embryos. Whichever method you choose, your chance of pregnancy remains the same.
The main difference between egg freezing and embryo freezing is that the latter requires sperm.
Egg freezing involves retrieving your good-quality eggs and freezing them for future use. As for embryo freezing, the collected eggs are fertilized and frozen for future use.
The female egg is made up of a single cell, which contains mostly water. When you freeze eggs, you are essentially removing all the water they contain and putting them in liquid nitrogen. Since an egg is just one big cell full of water, it is not as sturdy as an embryo. On the other hand, embryos are made up of many cells (up to 100) and are therefore stronger. An embryo still has a lot of structure to it, even after all the water in it has been removed.
If you want to freeze your eggs, you will need to take fertility medications for up to 2 weeks. This is in order to stimulate your ovaries to produce a large number of eggs. You will also be monitored to ensure that your eggs are maturing. This is done via ultrasound. Once your eggs are ready to be retrieved, you will go through the egg retrieval process under mild sedation. This process involves the use of a nonsurgical vaginal retrieval method with the help of an ultrasound. The eggs are then flash-frozen (vitrification) after retrieval.
But if you have a sperm donor or a partner at that time, your eggs can be fertilized with sperm. The resulting embryos will be frozen.
While neither procedure is no longer considered experimental, they still are not recommended as “fertility insurance.”
There are many reasons why people choose to freeze their eggs or embryos. Women with cancer who are planning to undergo treatment are the first group that always lead this topic. They freeze their eggs before treatment. The hope is that they can use them to have a baby in the future.
Egg freezing may also be the “go-to” procedure for partners who will undergo IVF treatment but would not like to freeze their embryos. To be specific, embryo freezing is usually an option for couples or individuals who are trying to conceive via in vitro fertil