Fast and furious: pregnancy outcome with one-step rehydration in the warming protocol for human blastocysts J Liebermann et al. Published:November 21, 2023.

This study aimed to compare the effectiveness of a streamlined one-step rehydration protocol for warming embryos to the standard multi-step procedure. The retrospective cohort study, encompassing 3439 frozen embryo transfers (FET), involved a detailed analysis of outcomes. The one-step rehydration protocol, applied in 833 FETs, was contrasted with the control group, comprising 2606 FETs utilizing the multi-step rehydration method.

Results indicated identical survival rates of 99.5% between the two groups. The clinical pregnancy rate for the one-step protocol was 63.0%, comparable to the multi-step protocol's 59.9%. Notably, the ongoing pregnancy rate demonstrated a significant increase with the one-step rehydration (60.4%) compared to the multi-step group (55.4%) (p=0.011). Similarly, the implantation rate was higher in the one-step protocol (63.6% vs. 57.0%, p=0.0005), while the miscarriage rate was significantly lower (4.0% vs. 7.6%, p=0.0001).

These findings persisted across PGT tested and untested embryos, as well as different blastocyst developmental stages. The study concludes that the one-step rehydration protocol not only achieved identical survival rates but also led to improved ongoing pregnancy rates compared to the multi-step technique

Source: J Liebermann et al - https://www.rbmojournal.com/article/S1472-6483(23)00830-1/fulltext