Everything You Need to Know About Fresh and Frozen Embryo Transfers
When many people begin their fertility journey, they often assume that the in vitro fertilization (IVF) process will result in a freshly created embryo being implanted into the intended mother’s uterus. While fresh embryo transfers are common, there is another option that is gaining popularity – frozen embryo transfer.
In frozen embryo transfer, the formation of the embryo remains the same as it does in a fresh transfer – eggs are extracted from the ovaries and fertilized with sperm in a laboratory. The ensuing embryos are then left to develop in the lab for about five to six days. However, instead of immediately implanting the embryos into the recipient’s uterus, the embryos are frozen so that they can be implanted at a later date.
How Embryos Are Frozen
Embryos are frozen using a rapid flash-freezing method known as vitrification. In this process, the embryos are treated using cryoprotectants that help protect the cells during the freezing and future thawing processes. The embryos are then frozen at a rapid rate, which prevents water molecules from solidifying into ice crystals. The result is a glasslike structure that can stay in frozen stasis for an indefinite period of time.
Why Choose Frozen Embryo Transfer?
One of the most common reasons people choose frozen embryo transfer is that they plan to have more than one child but only want to do one round of IVF. In this scenario, the woman goes through IVF as normal and then undergoes fresh embryo transfer while freezing the rest of the embryos. Later, when she is ready to grow her family, she already has a batch of frozen embryos available and can skip the first part of IVF.
However, some people are now choosing frozen embryo transfer over fresh embryo transfer altogether. The key benefit of frozen embryo transfer is that it allows you to delay implantation until your hormones have recovered from the IVF process.
In IVF, fertility medications are used to stimulate the ovaries, which results in higher levels of estrogen than you would typically see in a normal menstrual cycle. In a normal menstrual cycle, the production of estrogen triggers ovulation as well as the production of another hormone known as progesterone, which prepares the endometrial lining of the uterus for implantation. However, in IVF, the artificially elevated level of estrogen can sometimes cause the progesterone level to increase too early.
As such, the endometrial lining sometimes develops before the embryo can be implanted, making it difficult for the embryo to successfully attach to the uterine wall. However, when using frozen embryo transfer, you can delay implantation to a later cycle when your progesterone level can be timed more efficiently, thus improving the chances of having a successful embryo implantation.
Frozen embryo transfer is a great option for many people and is part of our standards of care in IVF at Aspire Fertility. To learn more, contact us today.