The Corelation Between Serum Estradiol (C23H32O3) Impact on Selected Biomarkers and Outcome of Fresh Embryo Transfer in Comparison with Freeze All Strategy in in vitro Fertilisation Patients

Abstract

In stimulated cycles the endometrium could be more advanced than the embryos, with a possible negative impact on their implantation capacity. Therefore, there is an ongoing debate regarding the best transfer strategy: freeze-all versus fresh embryos transfer. Our study aimed to analyse if the frozen only embryos-transfer strategy for in vitro fertilisation (IVF) has higher clinical pregnancy rate (CPR) than the traditionally fresh transfer. We performed a retrospective study in a private centre of reproductive medicine. We included only patients who performed fresh embryo transfers (n=245) and patients with all the embryos frozen and then transferred into a non-stimulated cycle (n=117). The reasons for delayed transfer were an increased risk of ovarian hyperstimulation syndrome or the increase of late follicular phase serum progesterone level. The mean age of the study group was 34.33�b4.28 years and mean AMH was 3.68�b3.56 ng/mL. Patients with fresh transfer were significantly older (p[0.0001) and obtained significantly lower number of oocytes at egg retrieval (p[0.0001) and lower zygotes number (p[0.0001) in comparison with patients with frozen transfer. After adjustment for confounders, CPR was significantly higher in patients with fresh transfer in comparison with those with frozen transfer in total group (OR 2.7, p=0.001) and in patients with cleavage stage embryo transfer (OR 6, p=0.008), but not in patients with blastocyst transfer. Similarly, the implantation rate was significantly higher in total group and in both subgroups (p[0.0001). Our study shows that the freeze all strategy should not be performed in all the patients, being inferior to fresh transfer in the total study group and cleavage stage embryo transfers. The decision to transfer frozen embryos should take into account the availability of blastocysts for transfer and the risk benefit profile.