A meta-analysis of 61 sperm count studies revisited

Stanley Becker, Kiros Berhane

Research output: Contribution to journalArticle

Abstract

Objective: To re-examine data on sperm counts over time from 61 studies from around the world. Design: Parametric analyses and flexible nonlinear models of the relation between sperm counts and time. Main Outcome Measure(s): Mean sperm concentrations per milliliter and regression coefficients for possible trends of concentrations over time. Result(s): A significant decline was found only in U.S. studies. Conclusion(s): Studies from specific sites have found declines in sperm counts, but a world-wide decline has not been demonstrated. Rigorous assessment of statistical models should be done before conclusions are drawn. Flexible smoothing models are a useful addition to currently available analytic methods.

Original languageEnglish (US)
Pages (from-to)1103-1108
Number of pages6
JournalFertility and Sterility
Volume67
Issue number6
DOIs
StatePublished - Jun 1997

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Sperm Count
Meta-Analysis
Nonlinear Dynamics
Statistical Models
Spermatozoa
Outcome Assessment (Health Care)

Keywords

  • Mean sperm counts
  • Meta-analysis
  • Statistical modeling

ASJC Scopus subject areas

  • Obstetrics and Gynecology

Cite this

A meta-analysis of 61 sperm count studies revisited. / Becker, Stanley; Berhane, Kiros.

In: Fertility and Sterility, Vol. 67, No. 6, 06.1997, p. 1103-1108.

Research output: Contribution to journalArticle

Becker, Stanley ; Berhane, Kiros. / A meta-analysis of 61 sperm count studies revisited. In: Fertility and Sterility. 1997 ; Vol. 67, No. 6. pp. 1103-1108.
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