The importance of estradiol measurement in patients undergoing in vitro fertilization

Successful outcomes of in vitro fertilization (IVF) are dependent in part on successful oocyte maturation and retrieval during a controlled ovarian stimulation process, which is guided by serial ultrasound and estradiol measurements. Yet, laboratory analysis of estradiol poses challenges due to the need for accuracy and specificity across concentrations that span multiple orders of magnitude. The Endocrine Society released a 2013 position statement that called for improvements in methods to analyze estradiol, and while some progress has been made in standardization and assay specificity, further work is needed to meet the needs of patients in both the IVF setting and in other clinical contexts. This review highlights the capabilities and challenges of current laboratory methods for the analysis of estradiol in the IVF setting, including automated immunoassays and liquid chromatography-tandem mass spectrometry, and discusses current efforts to improve the analytical sensitivity and standardization of estradiol assays. Clinical laboratorians should be aware of the limitations of current estradiol assays and select appropriate methods for the measurement of estradiol in their patient population.