How to balance the live birth rate and the multiple pregnancy rate by selecting the cleavage-stage embryo number and quality for POSEIDON Group 1 and Group 2? A retrospective study.

Purpose: For unexpected low-prognosis patients (Group 1 and Group 2) defined by POSEIDON criteria, how to maximize the live birth rate while controlling the multiple birth rate by tailoring the embryo transfer number and quality?
Methods: This was a retrospective study, including patients from Poseidon Group 1 (N = 672) and Group 2 (N = 503) who underwent cleavage-stage embryo transfer. Logistic regression was used for the comparative analysis of clinical outcomes among subgroups divided by the number and quality of embryos.
Results: For Group 1, compared to transferring a single good-quality embryo (GQE), a good-quality embryo with a poor-quality embryo (GQE + PQE) did not significantly improve the live birth rate, although increasing in value (40.5% vs 31.9%, P = 0.272), meanwhile obviously raised the multiple birth rate to 28.1% (P = 0.042). For Group 2, double embryo transfer (DET) was associated with a higher live birth rate than single embryo transfer (SET) (22.4% vs 6.3%, P = 0.001) and further analysis indicated that the similar trend observed in the GQE + PQE group compared to the GQE group (26.1% vs 8.5%, P = 0.017) with statistical significance, but without a significant increase in the multiple birth rate (8.3%, P = 1.000).
Conclusions: The study indicated that  a single good-quality cleavage-stage embryo was an option for patients in Poseidon Group 1 to avoid the risk of multiple pregnancies. DET with mixed quality cleavage-stage embryo might be an alternative for Poseidon Group 2, given that it improved the pregnancy outcomes while controlling the multiple birth rates.
Competing Interests: Declarations. Conflict of interest: The authors declare no conflict of interest. Ethics approval: This study has been approved by the Ethics Review Committee of Shenzhen Hospital of Peking University. Consent to participate: Not applicable. Consent to publish: This manuscript is approved by all the authors for publication.
(© 2024. The Author(s).)