Effect of vitrification on human oocytes: a metabolic profiling study

Objective To evaluate the effect of oocyte vitrification in the metabolomic profile of embryos developed from vitrified and fresh oocytes in our ovum donation program. Design Analysis of the metabolic profiles of spent culture medium samples corresponding to embryos developed from vitrified and fresh oocytes. Setting In vitro fertilization (IVF) unit/metabolomic facility. Patient(s) Oocyte donors between the ages of 18 and 35 years. Intervention(s) Metabolomic profile liquid chromatography coupled with mass spectrometry (LC-MS) of spent media samples. Main Outcome Measure(s) Identification of spent media components and metabolites present and absent in vitrified and fresh day-3 embryos. Result(s) We obtained a total of 190 spent media samples: vitrification group (65), fresh group (59), and a matched control media group (66). Multivariate data analysis was performed after global metabolomic and amino acid profiles did not reveal any statistically significant differences in day-3 embryos derived from fresh and vitrified oocytes, indicating that other metabolic differences between the samples (e.g., patient-to-patient variability, analytical variation) are greater than those between the vitrified and fresh sample groups. Univariate statistical analysis revealed a series of possible biomarkers, such as tryptophan, phenylalanine, and 2,5,7,8-tetramethyl-2-(2′-carboxyethyl)-6-hydroxychroman (alpha-CEHC), although only alpha-CEHC was statistically significant after correction for multiple testing. Conclusion(s) Multivariate data analysis did not reveal statistically significant differences between the analyzed groups, suggesting that oocyte vitrification does not disturb embryonic metabolomic profiles.