title: Seasonal onset of the menopause.
abstract: OBJECTIVE
  A seasonal rhythm of reproduction is evident in humans. Herein it was investigated whether also the cessation of woman's fertile life follows a seasonal rhythm.
  
  
  METHODS
  A retrospective study was performed on 2436 women in postmenopause for more than 12 months, in our menopause centres. Time of menopause was stratified for month and season. The variation was compared to the seasonal rhythm of 14,310 conceptions.
  
  
  RESULTS
  The onset of menopause was more frequent (p<0.0001) in winter (32.5%) than in spring (20.8%), autumn (20.3%) and summer (26.2%), in which a minor peak was also observed (p<0.0001 vs. spring and autumn). The two peaks were temporally coincident with the transitions between the high to low and low to high rate of conceptions.
  
  
  CONCLUSIONS
  The present data show that in women, like reproduction also the onset of menopause shows a seasonal modulation.
authors.affiliation: Dipartimento Misto Materno Infantile, Unità di Ginecologia e Ostetricia, Policlinico di Modena, via del Pozzo 71, 41100 Modena, Italy. cagnacci@unimore.it
authors.forename: A
authors.initials: A
authors.lastname: Cagnacci
authors.forename: F S
authors.initials: FS
authors.lastname: Pansini
authors.forename: A
authors.initials: A
authors.lastname: Bacchi-Modena
authors.forename: N
authors.initials: N
authors.lastname: Giulini
authors.forename: G
authors.initials: G
authors.lastname: Mollica
authors.forename: D De
authors.initials: DD
authors.lastname: Aloysio
authors.forename: E
authors.initials: E
authors.lastname: Vadora
authors.forename: A
authors.initials: A
authors.lastname: Volpe
mesh_terms: D000367:Age Factors; D001723:Birth Rate; D005260:Female; D006801:Humans; D008593:Menopause; D036801:Parturition; D012189:Retrospective Studies; D012621:Seasons