Which are the determining factors influencing the success rate of egg donation programmes with imported vitrified oocytes?

Abstract

Reserch question

Which are the determining factors influencing the success rate of egg donation programs with imported vitrified oocytes?

Design

Observational longitudinal cohort study of 431 cycles of oocyte donation conducted between January 2015 and February 2019. A total of 398 couples underwent an IVF cycle with imported donated vitrified. All consecutive oocyte donation cycles conducted at the centre for Reproductive Medicine of the European Hospital in Rome, Italy were included.

Results

A univariate analysis was carried out showing that among the demographic characteristics studied, the only one that proved significantly able to influence the outcome of the pregnancy test was male BMI. In 49% of unsuccessful cycles, the male BMI was above 25 (p=0.03). The relationship between female or donor BMI and treatment outcome, however, was not statistically significant. The day on which embryo transfer is performed affects the outcome of the cycle: transferring on day 2 compared to day 5 reduces the probability of clinical pregnancy. The relationship between male BMI classes and sperm parameters was studied: particular, obese men have a significantly lower concentration than normal-weight men (p=0.006 after Bonferroni correction). There were no statistically significant differences in volume (P=0.722), morphology (p=0.100) and motility (p=0.179), although there was a downward trend in motility, with a reduction in obese subjects compared to normal weight.

Conclusion

Our study shows that the number of oocytes available after warming, male BMI, semen characteristics and blastocyst transfer are critical parameters able to influence the reproductive outcomes of egg donation programs with imported vitrified oocytes.