What Is a Fresh Embryo Transfer?

A fresh embryo transfer involves transferring an embryo into the uterus during the same IVF cycle in which the eggs were retrieved and fertilized.

Here’s how it works:

1. Ovarian stimulation: Medications are used to encourage the ovaries to produce multiple mature eggs.
2. Egg retrieval: Once the eggs are ready, a minor surgical procedure is performed to collect them.
3. Fertilization: The eggs are combined with sperm in the lab to create embryos.
4. Embryo culture: The embryos are observed for a few days (usually 3–5) to determine which are developing normally.
5. Transfer: A healthy embryo is selected and transferred into the uterus while the endometrium (uterine lining) is still in its hormonally stimulated state.

Pros:

• One continuous process. No waiting period between egg retrieval and transfer.
• Often recommended when hormone levels are balanced and the uterine environment is optimal.

Things to consider:

• If hormone levels are too high (which can happen after ovarian stimulation), a fresh transfer might increase the risk of complications like ovarian hyper-stimulation syndrome (OHSS).
• In such cases, your care team might suggest freezing the embryos instead.

What Is a Frozen Embryo Transfer (FET)?

A frozen embryo transfer uses an embryo that was previously created and cryopreserved (frozen) during an earlier IVF cycle. The embryo is thawed and transferred in a future cycle, often weeks, months, or even years later.

Here’s the general process:

1. Embryo freezing: After fertilization and embryo culture, good-quality embryos are frozen using a method called vitrification.
2. Cycle preparation: In a future cycle, the uterine lining is prepared either naturally (monitoring ovulation) or with hormone medications to ensure it’s ready to receive the embryo.
3. Thawing and transfer: A frozen embryo is gently thawed and transferred into the uterus when the endometrium is at the ideal thickness and receptivity.

Pros:

• Gives the body time to recover from ovarian stimulation.
• Offers flexibility in timing the transfer, which can reduce physical and emotional stress.
• Lower risk of OHSS.
• Increasingly high success rates thanks to improved freezing techniques.

Things to consider:

• Requires excellent lab facilities for embryo freezing and thawing.
• There’s a short waiting period before transfer, which some find emotionally challenging.

Which Option Is Right for You?

Both fresh and frozen embryo transfers are widely used and have helped countless families grow. The decision is deeply personal and based on your health, fertility history, hormone levels, and sometimes the quality of your embryos or your body’s response to stimulation medications.

Your fertility team will guide you toward the best approach to optimize your chances of a healthy pregnancy by always keeping your safety, comfort, and goals at the center of the process.