Short communication: seasonal onset of menopause?

Background: Seasonal variations of reproductive functions in wild mammals are well known. Similar but blunted seasonal trends have also been described for humans.
Methods: We performed a questionnaire-based study of 149 patients that was designed to search for environmental influence on symptom presentation among patients attending an open menopause service.
Results: The evaluated data show a conspicuous seasonality in cessation of menstrual bleeding, with a higher peak after the vernal (spring) equinox and a lower one after the autumn equinox.
Conclusions: Of the several environmental factors considered in this study, the sequence of seasons seems to affect most obviously the process leading to the loss of menstrual cycling. The triggering factor(s) eliciting the onset of the menopausal process and the mediators involved, however, need further analysis.