Trend in menarcheal age and socioeconomic influence in Bologna (Northern Italy)

Temporal variations in menarcheal age in the Bologna province (northern Italy) were investigated in a sample of 2930 women born between 1930 and 1973, examined by retrospective method. A decrease in mean menarcheal age between birth decades 1930-39 and 1950-59 was noticed. The trend was more intense in lower social classes living in extra-urban environments. This led to a disappearance in menarcheal age differences between city and province and between socioprofessional categories. From birth decade 1950-59 onwards an increase in menarcheal age is registered, and an influence of physical activity and family structure on the age of menstrual cycle onset is observed. Our results suggest that the secular trend towards earlier age at menarche has stopped in the Bologna area. We hypothesize that the recent delay in puberty could be a response to an increase in physical and psychosocial stress.