Early Blastocyst Transfer in Young Women with Good Prognosis
Yes, an early blastocyst (day 5) is an excellent embryo for transfer in a woman under 35 years old with good ovarian response and sufficient high-quality embryos, and you should transfer only a single blastocyst regardless of its developmental stage or quality. 1, 2
Mandatory Single Embryo Transfer Protocol
The European Society of Human Reproduction and Embryology (ESHRE) provides a strong recommendation that single embryo transfer (SET) must be applied in all vitrified-warmed blastocyst transfer cycles regardless of the quality of the blastocyst. 1, 2 This applies to your patient scenario even though she has excellent prognostic factors.
Key Transfer Guidelines
- Transfer only one blastocyst, even when multiple high-quality embryos are available 1, 2
- The decision to transfer two embryos should never be based on embryo quality, previous failed cycles, duration of infertility, or patient age 2, 3
- Blastocyst transfer carries a 30-fold higher multiple pregnancy rate with double embryo transfer compared to repeated single embryo transfer (OR 30.54,95% CI 7.46-124.95) 3
Clinical Outcomes with Blastocyst Transfer
Blastocyst stage transfer significantly improves live birth rates compared to cleavage stage transfer. 4 The evidence shows:
- Live birth rates increase from 31% with cleavage stage to 38.8% with blastocyst transfer (Peto OR 1.40,95% CI 1.13-1.74) 4
- For patients with at least four good-quality embryos on day 3, blastocyst transfer results in 47.5% live birth rate versus 27.4% with day 3 transfer (OR 2.40,95% CI 1.25-4.59) 5
- Ongoing pregnancy rates are significantly higher with blastocyst transfer: 51.3% versus 27.4% for cleavage stage (OR 2.78,95% CI 1.45-5.34) 5
Why Early Embryo Quality Doesn't Predict Blastocyst Success
Day 2 and day 3 embryo morphology are poor predictors of blastocyst quality and implantation potential. 6, 7 The research demonstrates:
- Only 48% of embryos selected for transfer on day 3 would actually be used at the blastocyst stage 7
- Good-quality blastocysts have comparable implantation rates (38.7% versus 41.4%) regardless of whether they were classified as good or poor quality on day 2 6
- Extended culture to blastocyst stage enables better discrimination of embryonic viability than day 3 assessment 7
Critical Pitfalls to Avoid
Never transfer two blastocysts based on the rationale that you have multiple high-quality embryos available. 1, 2 Common errors include:
- Assuming that good prognosis patients can safely receive double embryo transfer—this dramatically increases multiple pregnancy complications including preeclampsia, gestational diabetes, emergency cesarean section, and preterm labor 3
- Believing that transferring two embryos with a plan for fetal reduction if both implant is acceptable—this practice is explicitly not recommended 1, 2
- Thinking that monozygotic twinning risk with blastocysts justifies avoiding blastocyst transfer—the solution is SET, not avoiding blastocysts 1
Patient Counseling Requirements
Healthcare professionals must discuss with the patient the medical, economic, social, and psychological consequences of transferring more than one embryo. 1, 2 Emphasize that:
- Cumulative live birth rates with repeated SET are equivalent to double embryo transfer while avoiding twin risks 3
- Even singleton pregnancies after double embryo transfer carry higher risks of neonatal death and complications compared to SET 3
- The ectopic pregnancy risk increases up to 20-fold with the number of embryos transferred 3