Purpose: To systematically evaluate the effect of maternal and embryonic factors on in vitro fertilization and embryo transfer (IVF-ET) outcomes among Chinese patients after using hyaluronan-enriched transfer medium (HETM).
Methods: This retrospective study included 637 frozen-thawed ET cycles. Patients were divided into subgroups based on their maternal or embryonic status or treatment procedures. The implantation, clinical pregnancy, delivery, and abortion rates were compared between the HETM and control groups. In addition, the implantation and clinical pregnancy rates were used to analyze the reciprocal effect of HETM and Preimplantation genetic screening (PGS) assessment.
Results: Maternal risk factors, especially maternal aging and a low number of retrieved oocytes, have a significant adverse impact on the efficacy of HETM usage. Endometrial preparation with artificial and natural cycles but not stimulated cycles showed a satisfying outcome after IVF-ET treatment. Compared with cleavage embryos, blastocyst stage embryo transfer showed more prominent improvement when using HETM. Prolonged pre-equilibration treatment with HETM notably compromised the IVF-ET outcome. PGS-based preselection could further facilitate the HETM-induced beneficial effect on IVF-ET outcomes. The body weight, length, and sex ratio of the neonate did not significantly differ between the HETM and control groups.
Conclusion: Both the maternal and embryonic status or treatment procedures affected the IVF-ET outcomes after using HETM. HETM had a beneficial effect on advantaged IVF cycles but did not improve the outcomes of disadvantaged IVF cycles. Endometrial preparation with stimulated cycles is not recommended when using HETM. Prolonged pre-equilibration treatment must be avoided.
Keywords: Embryo transfer; Frozen-thawed embryos; Hyaluronan; IVF; Implantation rate; Pregnancy rate.