Trend in menarcheal age in Spain: rural and urban comparison during a recent period.

Menarcheal age of a sample of rural (n = 342) and urban (n = 469) girls with ages ranging from 9 to 16 years from Madrid province was analysed. Results, obtained through the status quo method and probit analysis (age 12.79 SD 1.04 in Madrid city and 12.90 SD 1.03 in rural sample), were compared with data from previous studies carried out in the same area, as well as those from other regions of the Iberian Peninsula. The aim of these comparisons was to establish the variability of menarche in the recent past, considering physical environment, degree of urbanization and socio-economic development. Decline in menarcheal age was detected and, in general, a tendency towards similar means among Spanish populations in the period studied.