What Does a Single Semen Sample Tell You? Implications for Male Factor Infertility Research
Year: 2017
Type: article
Abstract: Semen parameters are variable within individuals, but it is unclear whether 1 semen sample could represent a man's long-term average values in epidemiologic studies. Between 2005 and 2014, a total of 329 men from a fertility clinic in Boston, Massachusetts, provided 768 semen samples as part of the Environment and Reproductive Health (EARTH) Study. Total sperm count, sperm concentration, morphology, motility, and ejaculate volume were assessed. We used linear mixed models to compare values from men's first semen samples with their long-term averages and to calculate intraclass correlation coefficients for each parameter. We calculated positive predictive values (PPVs) and negative predictive values (NPVs) by comparing agreement in classification according to World Health Organization reference limits. There were no differences in mean semen parameters between men's first samples and the remaining replicates. Intraclass correlation coefficients ranged from 0.61 for morphology to 0.75 for concentration, indicating consistently greater between-man variability than within-man variability. Nevertheless, using 1 sample alone resulted in high NPVs but low PPVs (range, 43%-91%). The average of 2 samples was needed to achieve high PPVs (range, 86%-100%) and NPVs (range, 91%-100%). We conclude that 1 semen sample may suffice for studies aimed at identifying average differences in semen quality between individuals. Studies aimed at classifying men based on World Health Organization reference limits may benefit from collection of 2 or more samples.
Source: American Journal of Epidemiology
DOI: 10.1093/aje/kwx169
Authors: Yu-Han Chiu, Regina Edifor, Bernard A Rosner, Feiby L Nassan, Audrey J Gaskins, Lidia Mínguez-Alarcón, Paige L Williams, Cigdem Tanrikut, Russ Hauser, Jorge E Chavarro, for the EARTH Study Team
Institution: Harvard University
Language: English
Subfield: Reproductive Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $4,856
Funders: Brigham and Women's Hospital, Massachusetts General Hospital, Harvard University, Harvard Catalyst, Harvard T.H. Chan School of Public Health, National Institutes of Health, National Institute of Environmental Health Sciences, National Institute of Child Health and Human Development, National Center for Research Resources, National Center for Advancing Translational Sciences, Eunice Kennedy Shriver National Institute of Child Health and Human Development
Awards: Human Exposure to Bisphenol A, Phthalates and Fertility, Pregnancy Outcomes, G1817070853, G2399921971, G2661966628, G3582335599, G3615943839, G3723922144, Harvard Chan School NIEHS Center for Environmental Health, G5426008394, G6361112147, G6424384527, G7060033699, Maternal Exposure to Air Pollution and Early Pregnancy Outcomes, Harvard Clinical and Translational Science Center, G9000014778
OpenAlex ID: W2617800152