title: [Natural fertility in couples and epidemiological aspects of subfertility].
abstract: BACKGROUND
  In the last 40 years, fertility rates in Western societies have been declining as a result of lifestyle and generative behavior.
  
  
  OBJECTIVE
  This review summarizes current evidence-based knowledge on natural infertility and epidemiological aspects of subfertility.
  
  
  METHODS
  A literature search on natural infertility and epidemiological aspects of subfertility was performed and the available data were structured and put in context.
  
  
  RESULTS
  After six unsuccessful cycles, slight or potentially severe subfertility should be assumed. Female age, number of unsuccessful cycles, ovarian reserve, and the results of sperm analysis determine the reproductive potential of a subfertile couple. An early measurement of anti-müllerian hormone levels and a sperm analysis are recommended.
  
  
  CONCLUSIONS
  Fertility awareness has gained increasing importance, not only in contraceptive use but also in optimizing individual fertility.
authors: green-ivf, Grevenbroicher Endokrinologie- und IVF-Zentrum, Rheydter Str. 143, 41515, Grevenbroich, Deutschland, dr.christian.gnoth@green-ivf.de.
authors: C
authors: C
authors: Gnoth
mesh_terms: D017677:Age Distribution; D054304:Anti-Mullerian Hormone / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D007246:Infertility / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology*; D038622:Internationality; D008297:Male; D065851:Ovarian Reserve; D010353:Patient Education as Topic / Q000706:statistics & numerical data*; D012307:Risk Factors; D055101:Semen Analysis / Q000706:statistics & numerical data*; D012737:Sex Factors
chemical_list: D015415:Biomarkers; D054304:Anti-Mullerian Hormone