Elective Single Embryo Transfer Recommendations
Introduction to Elective Single Embryo Transfer
- The European Society of Human Reproduction and Embryology (ESHRE) guidelines state that no clinical or embryological factor justifies a recommendation of double embryo transfer (DET) instead of elective single embryo transfer (eSET) in IVF/ICSI, including previous pregnancy loss, number of failed cycles, or duration of infertility 1, 2, 3, 4, 5
Risks Associated with Double Embryo Transfer
- The multiple pregnancy rate is 30-fold higher with DET compared to repeated SET, with an odds ratio of 30.54 (95% CI 7.46-124.95) 6, 7
- Pre-eclampsia, gestational diabetes, and emergency cesarean section rates are all elevated with multiple pregnancies 6, 7
- Preterm labor risk is substantially increased with DET 6, 7
- Even singleton pregnancies after DET carry higher risks of neonatal death and complications compared to SET 6, 7
- The risk of ectopic pregnancy increases up to 20-fold with the number of embryos transferred 6, 7
- The risk of monozygotic twinning is higher with blastocyst transfer, creating twin risk even with SET 6, 7
Benefits of Elective Single Embryo Transfer
- The cumulative live birth rate after repeated SET is equivalent to a single cycle of DET 1, 2
- SET reduces the risk of multiple pregnancy complications, including preterm birth, low birthweight, maternal morbidity, and neonatal complications 6, 7
Counseling and Recommendations
- The American Society for Reproductive Medicine (ASRM) and ESHRE recommend that patients should be counseled on the medical risks, psychological burden, and financial implications of multiple pregnancy 6, 7
- The cumulative live birth rates with repeated SET are equivalent to DET while avoiding twin risks 1, 2
- Patients should be advised against assuming previous pregnancy loss indicates a need for DET, and against considering fetal reduction as a backup plan 3, 4, 5
Elective Single Embryo Transfer Guidelines
Introduction to eSET
- The European Society of Human Reproduction and Embryology (ESHRE) mandates elective single embryo transfer (eSET) for all donated embryo transfers, regardless of endometrial thickness, mild adenomyosis, or small ovarian cyst 8, 9
Management of Ovarian Cysts and Endometrial Assessment
- ESHRE guidelines state that endometrial characteristics should not determine whether to perform single versus double embryo transfer in frozen embryo transfer cycles, prioritizing avoiding multiple pregnancy risks 8, 9
- The focus should remain on preventing multiple pregnancy complications, which would be particularly problematic in a uterus with adenomyosis 8
Mandatory Single Embryo Transfer
- Only eSET should be practiced for patients undergoing ART with donated embryos, with no exceptions, as a strong recommendation that applies regardless of the number of previous unsuccessful treatments, duration of infertility, previous pregnancy or live birth history, endometrial characteristics, patient age, or ovarian response 8, 9, 10, 11
Patient Counseling
- Counsel the patient on the rationale for eSET and the risks of multiple pregnancy before proceeding, discussing that eSET is the standard of care for donor embryo transfers to minimize maternal and neonatal complications 8
Management of Donor Embryo Transfer with Thick Endometrium, Mild Adenomyosis, and Ovarian Cyst
Embryo Transfer Strategy
- The European Society of Human Reproduction and Embryology (ESHRE) provides a strong recommendation that elective single embryo transfer (eSET) must be practiced for all donated embryo transfers with no exceptions, regardless of previous unsuccessful treatments, endometrial characteristics, patient age, or presence of adenomyosis 12
Management of the Ovarian Cyst
- Ovarian cysts that appear as simple cysts less than 10cm, such as the 11mm ovarian cyst, fall into O-RADS category 2 (almost certainly benign) and require no intervention before embryo transfer 13
- Simple cysts less than 5cm can be managed with optional single follow-up within one year, and do not require removal or delay of embryo transfer 13
- If the cyst has complex features, referral to an ultrasound specialist or gynecologist is necessary for further characterization before proceeding with embryo transfer 13
Addressing the Thick Endometrium
- A thick endometrium on day 3 may represent normal proliferative phase changes or could indicate endometrial pathology requiring further evaluation with imaging or hysteroscopy if there are concerning features 13
Embryo Transfer Guidelines
Introduction to Endometrial Thickness
- An endometrial thickness of 8.6 mm is acceptable for embryo transfer and falls within the normal range for successful implantation 14, 15, 16
Critical Embryo Transfer Recommendations
- Single embryo transfer (SET) should be applied in vitrified-warmed blastocyst transfer cycles regardless of embryo quality, as recommended by the European Society of Human Reproduction and Embryology (ESHRE) 15, 16
- The decision to transfer multiple embryos should never be based on previous unsuccessful treatments, duration of infertility, or previous pregnancy history, according to the American Society for Reproductive Medicine (ASRM) guidelines 15, 16
Frozen Embryo Transfer Protocol After Multiple Failed Attempts
Core Transfer Strategy
- The European Society of Human Reproduction and Embryology (ESHRE) strongly recommends maintaining single embryo transfer (SET) for all frozen blastocyst transfers, even after multiple failures, as the decision to transfer multiple embryos should not be based on prior unsuccessful treatments 17
- ESHRE explicitly states that the number of previous unsuccessful ART treatments should not influence the decision to perform double embryo transfer, and this is a strong recommendation from the society 17
Common Pitfalls to Avoid
- ESHRE guidelines explicitly contraindicate increasing embryo number based on failed attempts, as this does not improve outcomes and is associated with increased risks 17