Perinatal outcomes for transfer of blastocysts vitrified and warmed in defined solutions with recombinant human albumin: 374 babies born after 898 embryo transfers

Purpose

To assess the efficacy of a novel, defined vitrification procedure using recombinant human albumin (rHA) for cryopreservation of human blastocysts. Design: Retrospective study. Setting: Private IVF clinic. Patients: 1,496 patients received vitrified/warmed embryo transfer (ET).

Methods

Surplus blastocysts, and blastocysts from patients undergoing elective embryo cryopreservation, were vitrified/warmed using Cryotop carriers in homemade solutions containing either human serum albumin (HSA) or rHA. Main Outcome Measures: Clinical and neonatal outcomes regarding the vitrified/warmed ET procedures.

Results

The HSA and rHA groups had a total of 1,163 and 898 vitrified/warmed cycles, respectively. Embryo survival rates (98.7 % vs. 98.9 %, respectively) and the number of embryos transferred (1.08 ± 0.01 vs. 1.06 ± 0.01, respectively) were similar in the HSA and rHA groups. Clinical pregnancy rates/ET were higher (P < 0.05) in the rHA group (56.0 %) than in the HSA group (51.5 %). The HSA and rHA groups had similar live delivery rates/pregnancy (72.2 % vs. 72.3 %, respectively) and perinatal outcomes, including birth weight (2,988 ± 28 vs. 3,046 ± 26 g, respectively). Birth defects occurred in 0.9 % and 1.6 % of neonates in the HSA and rHA groups, respectively.

Conclusions

rHA effectively replaced HSA for human embryo vitrification procedures, and yielded high rates of pregnancy and live births after vitrified/warmed ET. This new approach will support the development of defined ART systems, which will eliminate the variation and risks associated with the use of blood-derived products.