Frozen Embryo Transfer (FET) vs Fresh Transfer: Which is Better?

The debate over the success of frozen embryo transfer vs fresh transfer is a hot topic. Earlier, when In-vitro Fertilization (IVF) was introduced, fresh transfer was the only viable way for couples to proceed with assisted reproductive technology. Later, cryopreservation (a method to freeze embryos for later use) went mainstream. 

This sparked many questions about the success rate of these methods. If you are also considering IVF, this post will walk you through the most notable differences between FET and fresh embryo transfer. By the end of this post, you’ll know the success rate of both, which one is suitable for your case, and the pros and cons of each. Let’s get started.

Understanding Frozen Embryo Transfer vs Fresh Transfer

Fresh and frozen embryo transfers are both parts of IVF. They involve the same series of steps, which start with ovarian stimulation (a process of stimulating your ovaries to produce and release multiple eggs in a single ovulation cycle). You are then scheduled for egg retrieval, a minimally invasive surgical procedure to collect these eggs from your ovaries for fertilization. 

Here’s what sets Fresh and Frozen transfers apart.

Fresh Embryo Transfer

As the name suggests, in fresh embryo transfers, the egg that’s fertilized with a sperm turns into an embryo, which is then monitored closely for 3-5 days. The embryo is transferred after a 5-day waiting period. 

Frozen Embryo Transfer 

Embryos can be frozen for later use. If a couple isn’t ready for pregnancy or they are advised to delay conception due to medical reasons, they can have their embryo frozen. When the couple is ready to have a child, these frozen embryos are thawed and transferred to the uterus.

The whole concept is based on freezing your embryos so they can be used when you are medically fit or mentally ready to conceive. Embryo transfer is timed based on your ovulation cycle. The fertility specialist may prescribe progesterone shots to prepare your uterine lining for implantation.

The main difference lies in the timing. There is no waiting period in fresh embryo transfers, whereas FET may require weeks or months. In some cases, couples may not decide to use their frozen embryo for years.

Which One is Better?

There is no clear-cut answer to which procedure is better. It depends on your health, fertility goals, and your gynecologist’s advice. Let’s see which option might be the most suitable for your case:

You are Young and Healthy

Women under 35 are good candidates for fresh embryo transfers, as their bodies can handle ovarian stimulation and implantation more effectively. 

You are at an Increased Risk of Ovarian Stimulation 

There’s a small risk of Ovarian Hyperstimulation Syndrome (OHSS) after ovarian induction. If you are at an increased risk, frozen embryo transfer could be a better option, as it allows your body the time needed to heal from ovarian induction. 

You have a Thin Uterine Lining

A successful implantation requires a thick uterine lining. If your ultrasound tests show a thin or unprepared uterine lining, your gynecologist might advise delaying embryo transfer. You may need progesterone shots to prepare your uterine lining. Until then, the embryos can be frozen. 

You Want to Try Preimplantation Genetic Testing (PGT)

PGT is a medical test that screens embryos for genetic or chromosomal defects. It’s a highly preferred test for parents with genetic diseases. If you want PGT, you may need to wait for the results so you can choose the healthiest embryo for implantation. This may require frozen embryo transfer.

You Want to Delay Pregnancy 

Frozen embryo transfer is a better choice for couples who are not ready to conceive yet but want to preserve their embryos in their prime reproductive years. Conception becomes trickier in advanced age. Cryopreservation offers the option to preserve your fertilized eggs, allowing them to be used when you are ready to conceive. 

You have a Tight Budget

A fresh embryo transfer procedure is a better choice for couples who can’t afford the cost of egg freezing. Fresh embryo transfer allows quick transfers (within 5 days of embryo culture).

Frozen vs Fresh Embryo Success Rates

A recent study published by the National Library of Medicine reveals that pregnancy was more likely in women who chose fresh embryos than in those who opted for FET. There was, however, only a small difference. 

Women who chose fresh embryos had a pregnancy rate of 21.8% while those who used frozen embryos had a success rate of 17.2%.

That said, the success rates can vary greatly for each woman. It depends on factors such as your age and ovulation cycle. 

Younger women who have regular cycles can benefit from fresh embryo transfers, but the ovarian stimulation medication can affect the uterine lining, making implantation comparatively more difficult than in FET.

Pros and Cons of FET Cycle vs Fresh Cycle

Fresh Transfer 

Pros

• Shorter waiting time
• Fewer procedures 
• Lower cost
• Good for young and healthy women 
• Slightly higher success rates than FET

Cons 

• Increased risk of OHSS (especially in PCOS patients)
• No time for recovery after ovarian induction 
• Unprepared uterine lining
• Less flexible

Frozen Embryo Transfer

Pros

• Lower risk of OHSS
• Enough time to prepare your physical and mental health for conception
• Good option for second attempts 
• Sufficient time for genetic testing

Cons

• Longer waiting period
• Comparatively expensive compared to a fresh transfer
• The embryo might not survive thawing, but that’s pretty rare

Conclusion

Fresh and Frozen are the two popular IVF embryo transfer options in Pakistan. Both have their share of benefits and risks. Fresh transfer can be a good choice for parents who can’t wait to conceive, while frozen transfer could be a better option for those who want to preserve embryos for future use. To get more details about each, discuss your requirements with a fertility specialist. They will be able to help you choose the procedure that best suits your health and needs. 

FAQs

Do I get to choose the number of embryos I can have implanted into my uterus?

Yes, you can. However, gynecologists often recommend a single embryo transfer to prevent the risk of multiple pregnancies.

How long can embryos thrive when frozen?

They can last for years or even up to a decade when stored properly and in the right environment. 

Which is the best option for me: fresh or frozen embryo transfer?

It depends on your individual circumstances. Some women have a fresh embryo transfer, while others who are at an increased risk of OHSS and other complications might go for a frozen embryo transfer. Both are safe and viable options.

Does FET or fresh transfer affect the baby’s development?

No, neither method has any effect on the baby’s cognitive or physical development. The quality of the embryo determines your baby’s health, which is why Preimplantation Genetic Testing is often recommended during IVF to reduce the risk of genetic abnormalities in the fetus.

Can I preserve embryos after a fresh transfer for future use?

Yes, you can preserve high-quality embryos for the frozen embryo transfer cycle.