Fresh and frozen embryo transfer: clinical questions to discuss

How to use this guide

This page provides the explanation. For a separate practical record, use Fresh or frozen transfer: itemised cost comparison worksheet. Record the responsible provider’s answers rather than treating a generic example as confirmation for your case.

Understanding Fresh and Frozen Embryo Transfer

When planning IVF in Thailand, one of the key decisions you will make with your fertility team is whether to have a fresh embryo transfer or a frozen embryo transfer. Both approaches are common, and the right choice depends on your individual medical situation, treatment plan, and clinic recommendations.

In a fresh transfer, an embryo is placed into the uterus a few days after egg retrieval, while still in the same cycle. In a frozen transfer, embryos are cryopreserved and transferred in a later cycle, after your body has recovered from ovarian stimulation. Each path has distinct timing, processes, and considerations.

At a Glance: Fresh vs Frozen Transfer

• Fresh transfer: A proposed transfer in the same treatment cycle; the clinic confirms the actual stage and timing.
• Frozen transfer: Embryos are frozen and transferred in a subsequent cycle, allowing time for planning and preparation.
• PGT (preimplantation genetic testing): If you plan to test embryos for genetic conditions, a frozen transfer is often necessary because testing takes time.
• Ovarian hyperstimulation syndrome (OHSS) risk: A frozen transfer may be recommended if you are at higher risk for OHSS after egg retrieval.
• Uterine receptivity: A frozen transfer allows your doctor to prepare your uterus with medication, potentially improving timing.

Fresh Embryo Transfer: Process and Timing

For a proposed fresh transfer, ask the clinic which clinical and embryology checks determine whether and when the transfer can proceed. A generic timeline is not an appointment confirmation.

Because the transfer happens in the same cycle, the overall treatment time is shorter. However, the hormonal environment after ovarian stimulation may not be ideal for implantation in some women. High estrogen levels from stimulation can affect uterine receptivity, and the risk of ovarian hyperstimulation syndrome (OHSS) may be increased.

When Might a Fresh Transfer Be Considered?

• If you have no increased risk of OHSS.
• If you prefer a shorter overall treatment timeline.
• If you are not planning to undergo PGT.
• If your doctor determines that your uterine lining is ready for transfer.

Frozen Embryo Transfer: Process and Timing

A frozen embryo transfer (FET) involves freezing embryos after fertilization and transferring them in a later cycle. The process begins with ovarian stimulation and egg retrieval, followed by fertilization and embryo culture. Embryos that are suitable for freezing are then cryopreserved using vitrification, a rapid freezing technique that helps protect them.

The actual transfer occurs in a subsequent cycle, which can be a natural cycle or a medicated cycle. In a medicated cycle, you may take medications to prepare your uterine lining. The timing of the transfer is planned based on your cycle and when the lining is optimal.

Because the transfer is separated from the stimulation cycle, your body has time to recover from the effects of fertility medications. This may reduce the risk of OHSS and allow for better uterine receptivity.

When Might a Frozen Transfer Be Considered?

• If you are at higher risk for OHSS.
• If you plan to undergo PGT, as testing takes time.
• If you need to delay transfer for personal or medical reasons.
• If your doctor recommends optimizing uterine receptivity.

Key Considerations for Your Decision

Ovarian Hyperstimulation Syndrome (OHSS)

OHSS is a potential complication of ovarian stimulation. Symptoms can range from mild discomfort to more serious issues. If you are at higher risk, your doctor may recommend a frozen transfer to allow your ovaries to recover before embryo transfer. Discuss your individual risk with your clinic.

Embryo Biopsy and PGT

If you are considering preimplantation genetic testing (PGT) to screen embryos for chromosomal abnormalities or genetic disorders, a frozen transfer is typically necessary. After embryo biopsy, cells are sent for analysis, which can take several days. By the time results are available, the window for a fresh transfer may have passed. Therefore, embryos are frozen and transferred in a later cycle.

Uterine Receptivity

The timing of embryo transfer is crucial for implantation. In a fresh transfer, the uterine lining is influenced by the high hormone levels from stimulation. In a frozen transfer, your doctor can prepare the lining with medication, potentially improving the chances of implantation. However, the best approach depends on your individual cycle and medical history.

Comparing the Two Approaches

Aspect	Fresh Transfer	Frozen Transfer
Timing	Same cycle as egg retrieval	Later cycle, after recovery
Overall treatment length	Shorter	Longer, due to break between cycles
OHSS risk	May be higher	May be lower, as transfer is delayed
PGT compatibility	Not usually possible	Necessary for PGT
Uterine preparation	Natural cycle after stimulation	Medicated or natural cycle, with more control

Questions to Ask Your Clinic

• What is your clinic’s recommendation for my specific situation, and why?
• What are the risks and benefits of fresh vs frozen transfer for me?
• If I plan to have PGT, how does that affect the transfer timing?
• What is the process for freezing and thawing embryos at your lab?
• How does my medical history (e.g., PCOS, endometriosis) influence the choice?
• What are the costs associated with each approach, including any additional freezing or storage fees?

Next Steps in Your Decision

1. Consult with your fertility specialist to review your medical history and stimulation plan.
2. Discuss whether PGT is recommended for you and how it affects transfer timing.
3. Ask about your risk for OHSS and how it might influence the transfer decision.
4. Consider your personal preferences for treatment length and scheduling.
5. Make a decision together with your doctor, based on medical evidence and your goals.

Remember, the choice between fresh and frozen embryo transfer is not about which is universally better, but which is more suitable for your individual circumstances. Your fertility team in Thailand will guide you based on your specific medical profile and treatment plan.

Continue your research

• Embryo transfer in Thailand guide
• IVF in Thailand guide
• Treatment journey

Medical information notice: This article is educational and does not replace individual assessment, diagnosis, genetic counselling or treatment advice from a licensed clinician. Provider services, availability, fees and policies should be verified directly before booking.