Embryo Freezing
What is an Embryo & How is it Created?
An embryo is the result of a fertilized egg. To create embryos in a lab, doctors first need to collect and fertilize eggs.
Here’s how the process works:
Hormone Treatment: The individual takes hormonal injections to control ovulation and increase egg production.
Egg Retrieval: A doctor collects the eggs from the ovaries using an ultrasound-guided procedure.
Fertilization:
IVF (In Vitro Fertilization): Eggs are combined with sperm in the lab and left to fertilize naturally.
ICSI (Intracytoplasmic Sperm Injection): A single sperm is directly injected into each egg. This is done when sperm quality is low or previous IVF attempts failed.
Once fertilized, the egg becomes an embryo. Embryologists monitor its growth for up to 6 days to identify healthy embryos for implantation or freezing.
How Are Embryos Frozen? The goal of freezing embryos is to preserve them for future use—such as during a later IVF attempt or after medical treatment that may impact fertility.
The Challenge: Embryos contain water, and if water forms ice crystals during freezing, it can damage the cells.
The Solution: Cryopreservation Doctors replace the water in the cells with a protective solution called a cryoprotectant, then freeze the embryo using one of two methods:
Slow Freezing: Embryos are cooled slowly in sealed tubes. This method reduces cell aging but requires more time and equipment.
Vitrification: Embryos are frozen rapidly to prevent ice crystal formation. This is faster and often results in higher survival rates upon thawing.
Frozen embryos are then stored in liquid nitrogen until needed.
Who Might Benefit from Embryo Freezing? Embryo freezing is a valuable option for:
Individuals with genetic conditions affecting fertility
Those undergoing chemotherapy or radiation
Patients on medications that may reduce fertility
What is a Frozen Embryo Transfer (FET)? A Frozen Embryo Transfer (FET) is a process where a previously frozen embryo is thawed and transferred into the uterus.
Benefits:
No need for another full IVF cycle
Can be done in a natural cycle or with hormonal support
Less physical and emotional stress
Why Do We Freeze Embryos? During IVF, multiple embryos are often created. Typically, only one is transferred to reduce the risk of multiple pregnancies. The rest can be frozen for future use.
This gives you multiple chances for pregnancy from a single egg retrieval, increasing the efficiency and reducing costs in the long run.