To characterize US clinical laboratory reference range reporting and testing methods of follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol, prolactin.
117 US laboratories were surveyed. Outcomes measured were variation in lower and upper limits of normal male reference ranges for serum follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol, and prolactin, method of analysis and source of reference range.
The upper limit of normal reference ranges for FSH, LH, estradiol, and prolactin varied substantially across laboratories compared to the lower limits. The range of upper limits of FSH, LH, estradiol, and prolactin respectively are 7.9-20.0, 4.9-86.5, 37.7-77.0, and 7.4-25.0. 94% of labs performed measurements on in-house high throughput analyzer utilizing immunoassays. 70% of reported reference ranges for each hormone were based on validation studies of the analyzer's package insert values. 10% of labs derived their own reference ranges. Both the validation studies and derivations were based on a limited number of patient samples, ranging from 20 to 200.
Current reference ranges are based on small population studies of men with unknown medical histories, sexual or reproductive function. Influence of race and age have not been evaluated and could potentially be important in normal variation. The absence of standard information has yielded a spectrum of upper and lower normal values, which could delay an appropriate male infertility evaluation. Our findings highlight the need for a large population study of males with known normal sexual and reproductive function to formulate more accurate clinical reference ranges.
Urology. 2018 Jul 26 [Epub ahead of print]
Frances Grimstad, Margaret Le, Andrew Zganjar, David Flores, Eric Gourley, Danica May, Ajay K Nangia
Ob/Gyn, University of Kansas Medical Center, Kansas City, Kansas. Electronic address: ., Department of Urology, University of Kansas Medical Center, Kansas City, Kansas. Electronic address: ., Department of Urology, University of Kansas Medical Center, Kansas City, Kansas. Electronic address: ., Department of Urology, University of Kansas Medical Center, Kansas City, Kansas. Electronic address: ., Department of Urology, University of Kansas Medical Center, Kansas City, Kansas. Electronic address: ., Department of Urology, University of Kansas Medical Center, Kansas City, Kansas. Electronic address: ., Department of Urology, University of Kansas Medical Center, Kansas City, Kansas; Ob/Gyn, University of Kansas Medical Center, Kansas City, Kansas. Electronic address: .