Declining ages at menarche in an agrarian rural region of Poland

Objective: Age at menarche in Poland has varied with political and socioeconomic changes. An increase in age at menarche corresponded to a period of economic crisis and food rationing between 1976 and 1989. Experiencing food shortages in utero or during childhood development can affect menarcheal timing, but this national effect may be buffered in local agrarian regions growing their own food. Here we examine patterns of age at menarche over time in the rural, agrarian Beskid Wyspowy region of southern Poland. Methods: This study examined menarcheal timing using data collected from Polish women (n = 1326) recruited at the Mogielica Human Ecology Study Site between 2003 and 2018. Simple linear regressions were used to assess changing ages at menarche over time. Comparisons between ages at menarche for women born before and after the fall of communism in 1989 were assessed via one-way analysis of variance. Results: Age at menarche has declined over time in the Beskid Wyspowy region of southern Poland from 1920 to 2000 (R² =.08, P <.0001). There was not a statistically significant increase or decrease in age at menarche for women born and growing up during the period of food rationing. Conclusions: The declining age at menarche is likely reflective of a transitioning environment, suggesting that major socioeconomic changes affect life history traits like pubertal timing. Living in agricultural regions may have helped buffer the increasing ages at menarche seen in other areas of Poland during times of food rationing.