Potential of inner cell mass outgrowth and amino acid turnover as markers of quality in the in vitro fertilization laboratory

Objective: To compare sensitivity of inner cell mass (ICM) outgrowth assay and analysis of culture media amino acid turnover with the sensitivity of the human sperm motility assay (HSMA) and murine embryo assay (MEA) for detection of formaldehyde toxicity. Design: Prospective in vitro study. Setting: University hospital-based infertility center. Animal(s): Murine embryos. Intervention(s): The HSMA, MEA, and ICM outgrowth assays were performed with media containing 0-64-μM concentrations of formaldehyde. These assays were compared with dynamics of amino acid turnover in culture media. Main Outcome Measure(s): The lowest concentration of formaldehyde in culture media detected by each quality control assay. Result(s): Sperm forward progression, but not motility, detected formaldehyde at a concentration of 32 μM. Sperm motility index identified formaldehyde toxicity at 64 μM, whereas blastocyst rates in the MEA were affected at 32 μM formaldehyde. Evaluation of ICM using outgrowth and grade detected 16 μM formaldehyde. Leucine turnover in culture media detected 64 μM formaldehyde in the amino acid assay. Conclusion(s): Inner cell mass outgrowth is a more sensitive bioassay than MEA and HSMA for the detection of formaldehyde in culture media. Amino acid metabolism may also provide a sensitive quality control measure for detection of formaldehyde.