Quality improvement in the laboratory assessment of in vitro fertilization

There has been a trend to use fewer laboratory tests during ovarian hyperstimulation prior to oocyte recovery, in vitro fertilization, and embryo transfer. Estradiol is routinely monitored during ovulation induction protocols. Estradiol rises steadily to supraphysiologic concentration during ovarian hyperstimulation. Review of the College of American Pathologists proficiency testing data from 1990 reveal that the within-method interlaboratory coefficient of variation meets the proposed maximum allowable analytical error of 11.8%. The luteinizing hormone level increases during ovarian hyperstimulation with a skewed distribution. Molecular variants exist that may bind with different affinities to monoclonal antibodies used in two-site sandwich assays. Polyclonal radioimmunoassays usually overestimate luteinizing hormone concentration. The College of American Pathologists proficiency testing data reveal that only three of eight methods with greater than 20 participants had a within-method interlaboratory coefficient of variation that met the proposed maximum allowable analytical error of 10% or less. International standardization of reference standards, antibodies, and labeling methods may improve the performance of this assay. The low pregnancy rate experienced by in vitro fertilization protocols suggests that additional laboratory tests need to be developed to monitor the receptivity of the endometrium for implantation and the quality of the oocyte and embryo.