Maturitas 51 (2005) 393–396 Seasonal onset of the menopause A. Cagnacci a,* , F.S. Pansini b , A. Bacchi-Modena c , N. Giulini e , G. Mollica b , D. De Aloysio d , E. Vadora c , A. Volpe a Emilia-Romagna Operative Group for Menopause (GOERM) a Dipartimento Misto Materno Infantile, Unit` a di Ginecologia e Ostetricia, Policlinico di Modena, via del Pozzo 71, 41100 Modena, Italy. b Department of Obstetrics Gynaecology and Paediatric Sciences, Gynaecology Units of Policlinico of Ferrara, Ferrara, Italy c Department of Obstetrics Gynaecology and Paediatric Sciences, Gynaecology Units of Policlinico of Parma, Parma, Italy d Department of Obstetrics Gynaecology and Paediatric Sciences, Gynaecology Units of Policlinico of Bologna, Bologna, Italy e Department of Obstetrics Gynaecology and Paediatric Sciences, Division of Obstetrics and Gynecology of Cattolica, Cattolica, Italy Received 15 June 2004; received in revised form 13 October 2004; accepted 15 October 2004 Abstract Objectives: 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. © 2004 Elsevier Ireland Ltd. All rights reserved. Keywords: Menopause; Seasons; Reproduction; Humans 1. Introduction Seasonality of reproduction is a widespread phe- nomenon aimed to synchronise specie reproduction * Corresponding author. Tel.: +39 059 4224511; fax: +39 059 4224394. E-mail address: cagnacci@unimore.it (A. Cagnacci). to most favourable environmental conditions [1,2]. Although, this phenomenon is maximally evident in seasonal breeders, a seasonal variation of reproduction has been described also in species, as the human species, where conception is not strictly confined to some periods of the year [3,4]. The seasonal trend of human reproduction is present throughout the world, and is mainly dependent on information deriving from 0378-5122/$ – see front matter © 2004 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.maturitas.2004.10.002