Embryo exposure time to a hyaluronan-enriched transfer medium and live birth after fresh embryo transfer

Is the duration of embryo exposure to a hyaluronan-enriched transfer medium before fresh embryo transfer associated with live birth rate?

Monocentric retrospective cohort study of 1089 fresh embryo transfers carried out between February 2022 and July 2024. All fresh embryo transfers carried out during the study period with available automated timing data were included. Embryo exposure time to EmbryoGlue® was precisely measured using the RI Witness® automated traceability system. The primary outcome was live birth. Exposure times were analysed as quartiles and as a continuous variable using univariable and multivariable logistic regression models adjusted for maternal age, embryo developmental stage at transfer, number of embryos transferred and embryo quality.

Mean (± SD) embryo exposure time was 135.1 ± 81.3 min (range 1-407 min). Overall live birth rate was 26.4%. Live birth rates did not differ significantly across exposure time quartiles (P = 0.381). Multivariable logistic regression showed no significant association between exposure time and live birth rate (adjusted OR 0.999, 95% CI 0.997 to 1.001; P = 0.230). Similar results were observed in subgroup analyses according to maternal age (≥39 years) and embryo developmental stage (cleavage-stage or blastocyst).

No significant association was observed between embryo exposure time to EmbryoGlue and live birth rate after fresh embryo transfer, even after adjustment for major clinical and embryological confounders. These results suggest that, within the wide range of exposure times observed in routine practice, embryo exposure duration to EmbryoGlue does not influence live birth outcomes. This supports organizational flexibility in IVF laboratories without compromising clinical results.