Transferring two grades I cleavage-stage embryo might not be a good protocol

Area of Science:

• Reproductive medicine
• Embryology
• In vitro fertilization

Background:

• Cleavage-stage embryo transfer is a common practice in assisted reproductive technology.
• Selecting optimal embryos for transfer is crucial for improving pregnancy outcomes.
• The quality of embryos, particularly grade I cleavage-stage embryos, influences implantation and pregnancy rates.

Purpose of the Study:

• To evaluate the suitability of transferring two grade I cleavage-stage embryos in the first fresh embryo transfer cycle.
• To compare the clinical pregnancy and twin-pregnancy rates associated with different embryo transfer strategies.

Main Methods:

• Retrospective analysis of embryo transfer data.
• Inclusion of single and double embryo transfers across different embryo grades (I and III cleavage-stage, excellent blastocyst).
• Comparison of clinical pregnancy and twin-pregnancy rates as primary outcomes.

Main Results:

• Single excellent blastocyst transfers showed significantly higher clinical pregnancy rates than single grade I or III cleavage-stage embryos.
• Transferring two grade I cleavage-stage embryos achieved a clinical pregnancy rate comparable to single excellent blastocyst transfers.
• However, the twin-pregnancy rate was significantly higher in the double grade I cleavage-stage embryo transfer group compared to other groups.

Conclusions:

• Transferring two grade I cleavage-stage embryos may not be an optimal strategy due to a high incidence of twin pregnancies.
• Extended embryo culture to the blastocyst stage should be considered for patients with only two grade I cleavage-stage embryos to potentially improve outcomes and reduce multiple gestations.