IVF treatment continues to be a beacon of hope for thousands of couples dreaming of parenthood. One of the crucial decisions encountered during this treatment process is when to perform the embryo transfer: whether it will be "fresh" in the same cycle as the egg retrieval, or "frozen" by freezing the embryos and transferring them in a later cycle. Both approaches have their unique advantages and disadvantages, and making the right decision is critically important for the success of the treatment. As Ankara IVF Center, with over 30 years of experience from Prof. Dr. Kubilay Vicdan, we want to share the most current approaches and scientific data on this topic with you.
Differences between the two approaches
In IVF treatment, embryo transfer is the stage where fertilized eggs (embryos) are placed into the mother's uterus. This stage is divided into two main categories based on timing: fresh embryo transfer and frozen embryo transfer.
What is Fresh Embryo Transfer?
Fresh embryo transfer is the process where, after ovarian stimulation, egg retrieval, and fertilization, the resulting embryos are transferred into the mother's uterus within the same treatment cycle, typically 3 or 5 days after egg retrieval. In this method, embryos are placed directly into the uterus without undergoing any freezing procedure. The advantage is that the treatment is completed more quickly, and the patient can receive results sooner. However, the potential effects of medications used to stimulate the ovaries on the uterine lining (endometrium) or the patient's general health status can negatively impact the uterus's ability to accept the embryo.
What is Frozen Embryo Transfer?
Frozen embryo transfer (FET) is the process where, after egg retrieval and fertilization, the resulting embryos are frozen using special techniques for storage and then thawed and transferred in a later cycle (usually one or several months later). This approach allows time for the uterus to return to its natural hormonal balance and for the most optimal environment for embryo implantation to be prepared. Thanks to rapid freezing techniques called vitrification, the post-thaw survival rates of embryos have significantly increased. Frozen embryo transfer is a preferred method, especially when the uterine lining is not optimal, in patients at risk of Ovarian Hyperstimulation Syndrome (OHSS), or when preimplantation genetic testing (PGT) is required. You can find more information about our embryo and egg freezing service.
Freeze-all strategy
The "freeze-all" strategy means that all suitable embryos obtained after egg retrieval and fertilization in an IVF cycle are frozen without a fresh transfer being performed in that cycle, and the transfer is completely postponed. This strategy has gained increasing popularity in recent years due to growing scientific evidence and advancing freezing technologies. As Prof. Dr. Kubilay Vicdan and his team, we closely monitor the positive effects of this approach on our patients' health and treatment success.
The main goal of this strategy is to eliminate the effects of ovarian stimulation on the mother's body, thereby creating a more natural and optimal uterine environment for embryo implantation. High-dose hormone medications used to stimulate the ovaries can alter the structure and receptivity (the ability to accept an embryo) of the uterine lining. With the freeze-all strategy, the uterus is hormonally rested and returns to its natural cycle, which can increase the chances of embryo implantation.
The main reasons for choosing the freeze-all strategy are:
- Risk of Ovarian Hyperstimulation Syndrome (OHSS): The risk of OHSS can be high, especially in patients from whom many eggs are retrieved. Fresh transfer can increase the severity of this syndrome. Freezing all embryos eliminates this risk and protects the patient's health.
- Endometrial Receptivity Issues: During ovarian stimulation, the uterine lining may not develop as it should, or hormonal changes may make it unsuitable for embryo implantation. Freeze-all allows for transfer in a subsequent cycle when the uterus is in an ideal state.
- High Progesterone Levels: Elevated progesterone levels on or before the egg retrieval day can disrupt the timing of the uterine lining's receptivity to the embryo. Freeze-all eliminates this risk.
- Need for Preimplantation Genetic Testing (PGT): When embryos need to be genetically examined (PGT), results take a few days. During this period, embryos are frozen, and genetically healthy embryos are transferred later. You can find detailed information about our genetic testing (PGT) service.
- Additional Medical Conditions: Freeze-all may be preferred if the patient's current health status (e.g., infection, fever, need for another surgical intervention, etc.) is not suitable for a fresh transfer.
- Planning and Flexibility: For some couples, freezing embryos may be preferred to better plan the treatment process and reduce stress factors.
Thanks to modern vitrification techniques, the post-thaw survival rates of embryos are quite high, which increases the reliability of the freeze-all strategy. This strategy prioritizes the health of the expectant mother while increasing pregnancy rates, especially in specific patient groups.
Which situation calls for which?
The decision of whether to perform a fresh or frozen embryo transfer is meticulously evaluated by Prof. Dr. Kubilay Vicdan, based on each patient's individual situation, medical history, and response to treatment. As Ankara IVF Center, we conduct a comprehensive evaluation to determine the most suitable strategy for every couple. You can visit our page to learn about the step-by-step IVF process.
When is Fresh Embryo Transfer Preferred?
Fresh embryo transfer remains a suitable and successful option in many situations. It is generally considered in the following cases:
- Good Ovarian Response and Low OHSS