Undergoing ICSI but Not Ready for Pregnancy Yet?

FET May Be the Answer.

Undergoing ICSI but Not Ready for Pregnancy Yet? FET May Be the Answer.

ICSI or IVF treatment includes an important step that can affect the chances of a successful pregnancy: transferring the embryo into the woman’s uterine cavity. Generally, a fresh embryo transfer is performed during the same cycle as ovarian stimulation. However, another option that has become increasingly popular is Frozen Embryo Transfer (FET).

Freezing good-quality embryos first and transferring them at an appropriate time can help reduce certain potential risks and may also improve the chances of achieving a successful pregnancy.

FET and Preparing the Endometrium to Align with Embryo Transfer Timing

Frozen Embryo Transfer allows the medical team greater flexibility in planning the timing of embryo transfer. The endometrium can be prepared and the body’s response monitored before determining the embryo transfer date. Information from monitoring the endometrium and hormone levels is considered when planning the timing appropriately for each individual.

From Frozen Embryos to Embryo Transfer

Before a frozen embryo is transferred, it undergoes the thawing process to prepare it for transfer under suitable conditions. The Embryology Laboratory team evaluates the embryo after thawing and prepares it for transfer into the uterine cavity. Therefore, the laboratory process is another important part of FET.

FET and Choosing the Optimal Timing

One of the key advantages of FET is that the egg retrieval and embryo transfer can take place at different times. This gives the medical team more time to assess and prepare the body before entering the embryo transfer cycle, particularly when it is necessary to wait until hormone levels and the uterine environment are suitable.

FET and Family Planning

Embryo cryopreservation allows couples to preserve embryos for future treatment, meaning that having a child does not necessarily have to take place during the same period as ovarian stimulation and egg retrieval. This provides greater flexibility for family planning and allows couples to determine a timing that best suits their individual readiness and circumstances.

Frozen Embryo Transfer (FET) Process

Frozen Embryo Transfer, or FET, is a procedure in which embryos created through fertilization in the laboratory are frozen using the vitrification method. Frozen embryos at the blastocyst stage are thawed and then transferred into the woman’s uterine cavity. Unlike fresh embryo transfer, FET does not need to be performed during the same cycle as ovarian stimulation and egg retrieval. It can be scheduled when the woman’s body is ready or when it is convenient for the couple, and it may offer a relatively high chance of successful pregnancy compared with fresh embryo transfer.

5 Benefits of Frozen Embryo Transfer

Frozen Embryo Transfer offers several benefits that may help improve the chances of successful pregnancy, including benefits related to physical health, process precision, and flexibility in family planning. These include:

  1.  Allows Time for the Body to Recover and May Reduce the Risk of Side Effects from Ovarian Stimulation
    • After ovarian stimulation, the woman’s body undergoes rapid changes in hormone levels, which may lead to Ovarian Hyperstimulation Syndrome (OHSS), a condition in which the ovaries are excessively stimulated, or other adverse effects. If an embryo is transferred immediately after egg retrieval (Fresh Transfer), the body may not yet have returned to a balanced state, which may not be optimal for embryo implantation and may also affect the woman’s health.
  2. Allows More Precise Timing of Embryo Transfer
    • Frozen embryo transfer allows the timing of embryo transfer to be planned more precisely. The doctor and the woman can prepare the uterine lining in advance and determine the embryo transfer date to correspond with the period when the endometrium is most receptive to implantation, which may help improve the chances of pregnancy.
  3. Allows Selection of Embryos Through Chromosomal Screening
    • One of the advantages of FET is that embryos with normal chromosomes can be selected through genetic testing. PGT-M can be used to identify specific genetic abnormalities, which may help reduce the risk of certain genetic conditions and miscarriage and may increase the chance of a successful pregnancy.
  4. Supports Future Family Planning for Those Who Are Not Ready to Become Pregnant Immediately
    • Some couples may retrieve eggs and fertilize them in advance but may not yet be ready to have children at that time due to work, health, or life-planning considerations. Freezing embryos allows them to be stored for several years while maintaining their quality, providing flexibility to pursue pregnancy when the timing is more appropriate.
  5. Reduces the Complexity for Those Who Want More Than One Child Through ICSI or IVF
    • Whether undergoing IVF or ICSI, each treatment cycle requires considerable time, cost, and physical preparation. For couples planning to have more than one child, freezing multiple embryos during a single cycle and subsequently using them for FET can help reduce the burden of treatment costs and the effects of ovarian stimulation while making family planning more convenient.
When Is the Appropriate Time to Have FET and How Should You Prepare?

Frozen Embryo Transfer is commonly performed during one or two menstrual cycles after egg retrieval and fertilization, allowing the body time to fully recover and providing time for the woman to take care of her health and prepare the endometrium to reach an appropriate thickness. However, the embryo transfer can be postponed depending on the woman’s physical readiness, medical considerations, or the couple’s family-planning goals.

Preparation Before FET
  • Consume a high-protein diet and foods containing vitamins A, B, C, and E, while avoiding high-fat foods, raw foods, and fermented or preserved foods.
  • Avoid alcohol, smoking, and excessive caffeine consumption.
  • Get at least 7–8 hours of sleep per day to support the body’s recovery and normal functioning of various systems.
  • Avoid strenuous activities and excessive heat exposure, such as hot baths, saunas, or high-intensity exercise.
  • Engage in relaxing activities such as meditation, yoga, or reading to reduce stress and maintain emotional well-being.
  • Take medications and hormones prescribed by the doctor to prepare the uterine lining strictly according to instructions.
Who Is FET Suitable For?

Frozen Embryo Transfer offers several benefits in terms of health and family planning and may be suitable for couples who wish to have children through ICSI or IVF, particularly those with the following considerations:

  • Individuals at risk of developing ovarian hyperstimulation syndrome (OHSS) following hormonal ovarian stimulation.
  • Individuals who want to allow their body to recover after ovarian stimulation and egg retrieval so that the endometrium can return to its normal state.
  • Individuals who want to choose an embryo transfer timing that is appropriate for their health and physical readiness.
  • Individuals who want to perform embryo screening before transfer, such as testing for genetic abnormalities or assessing embryo quality.
  • Individuals who are unable to undergo fresh embryo transfer due to medical reasons or because their body is not yet ready.

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How Is FET Different from Fresh Embryo Transfer?

FET involves transferring embryos that have been frozen and thawed before being transferred into the uterine cavity, allowing the timing of embryo transfer to be selected based on the woman’s physical readiness and endometrial preparation. In contrast, Fresh Embryo Transfer involves transferring embryos during the same cycle as ovarian stimulation and egg retrieval.

FET is suitable for individuals who have frozen embryos and wish to transfer them during an appropriate cycle. It may also be suitable for individuals at risk of ovarian hyperstimulation syndrome (OHSS), those who want to allow their body to recover after ovarian stimulation, or those who are unable to undergo fresh embryo transfer for medical reasons.

FET can be planned when the body is ready and the endometrium is in an appropriate condition. The optimal timing varies from person to person. The doctor will assess the menstrual cycle, overall health, and readiness of the endometrium before determining the embryo transfer date.

Get adequate rest, eat a healthy and nutritious diet, avoid smoking and alcohol, avoid strenuous activities, and take medications or hormones to prepare the endometrium strictly according to the doctor’s instructions.

Embryos can be tested before transfer in certain cases, such as screening for chromosomal abnormalities or testing for genetic abnormalities when medically indicated. The doctor will determine the most appropriate type of testing for each couple before embryo transfer.