At a glance
For women over 40, frozen embryo transfer (FET) success depends on embryo quality, genetic testing, and uterine factors. This guide explains how PGT and other considerations affect outcomes in Thailand.
Understanding Frozen Embryo Transfer and Age
Frozen embryo transfer (FET) involves thawing and transferring a previously frozen embryo into the uterus. For women over 40, success rates are influenced by the embryo’s chromosomal health, which declines with age. Preimplantation genetic testing (PGT) can help select embryos with a normal number of chromosomes, potentially improving the chance of implantation and live birth. However, no test can guarantee pregnancy, and outcomes vary by individual.
Factors Affecting FET Success in Older Women
Embryo Quality and Genetic Status
Embryo quality is the strongest predictor of FET success. After age 40, a higher proportion of embryos are chromosomally abnormal, which often leads to implantation failure or miscarriage. PGT-A (aneuploidy screening) can identify euploid (normal) embryos for transfer. While PGT-A does not increase the number of viable embryos, it may reduce the time to pregnancy by avoiding transfers of abnormal embryos.
Uterine Receptivity
The uterine lining must be receptive for implantation. Factors such as endometrial thickness, hormone levels, and the presence of fibroids or polyps can affect success. Clinics typically assess the uterus via ultrasound or hysteroscopy before FET.
Number of Previous IVF Cycles
Women who have had multiple failed IVF cycles may have lower success rates with FET, though this is not always the case. Each cycle provides information that can guide adjustments.
Clinic Experience and Laboratory Standards
The quality of the IVF laboratory and the embryologist’s skill in freezing and thawing embryos are critical. Vitrification (ultra-rapid freezing) has improved survival rates for frozen embryos, but outcomes vary between clinics.
Role of Preimplantation Genetic Testing (PGT)
PGT is often recommended for women over 40 to screen embryos for chromosomal abnormalities. Types include:
- PGT-A: Screens for aneuploidy (extra or missing chromosomes).
- PGT-M: Tests for single-gene disorders (if indicated).
- PGT-SR: Detects structural rearrangements like translocations.
PGT can reduce miscarriage risk and increase the chance of a healthy live birth per transfer, but it does not guarantee success. Not all embryos will be suitable for biopsy, and some may not survive the process. Discuss with your clinic whether PGT is appropriate for your situation.
Questions to Ask Your Clinic
- What is your clinic’s FET success rate for women over 40 using PGT-screened embryos?
- How many embryos typically survive the freeze-thaw process?
- What is your approach to preparing the uterine lining for FET?
- Do you recommend PGT-A for all patients over 40, or only after multiple failures?
- What additional tests (e.g., endometrial receptivity array) do you offer?
Next Steps for Patients Over 40
- Consult a fertility specialist to review your ovarian reserve and overall health.
- Discuss the option of PGT-A to guide embryo selection.
- Ask about the clinic’s experience with FET in older patients.
- Consider a second opinion if you have had previous failed cycles.
- Plan for multiple cycles if needed, as embryo banking may improve cumulative success.
For more information, see our guides on PGT in Thailand and IVF guides, or visit our FAQ page.
Frequently asked questions
Does PGT-A improve FET success for women over 40?
PGT-A can help select chromosomally normal embryos, which may increase the chance of implantation and reduce miscarriage risk. However, it does not guarantee success, and some women may not have any euploid embryos to transfer.
How many FET cycles might I need over 40?
The number of cycles varies. Some women achieve pregnancy after one FET, while others may need multiple attempts. Embryo banking (freezing embryos from several egg retrievals) can improve cumulative success.
What is the typical cost of FET in Thailand?
Costs vary widely by clinic and whether PGT is included. Confirm all fees, including medication, lab work, and embryo storage, directly with the clinic.
Can I use donor eggs with FET if my own embryos are not viable?
Yes, donor egg embryos often have higher success rates for women over 40. Discuss this option with your clinic if you have few or no euploid embryos.
Continue your research
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.
Need help turning research into a shortlist?
