ArticleInternational journal of reproductive biomedicine2026
Secular trends in menarche age among Iranian girls: Probit analysis on cross-sectional data of Persian (Shahedieh) cohort.
Article in International journal of reproductive biomedicine, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
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Abstract
Background: Given concerns regarding changing puberty ages globally, examining current trends in specific societies is essential. Objective: This study aimed to determine secular changes in the age at menarche among Iranian girls in central Iran using the Probit model. Materials and Methods: This cross-sectional study utilized data from the entry phase of the Shahedieh cohort study, Yazd, Iran. In total, fertility information and menarche data were extracted from 4,854 women (aged 35-70 yr). Based on the menarche age data of these individuals, the proportion of those who had reached menarche in each of the 3 birth decades (1946-1957, 1958-1969, and 1970-1981) was calculated. To calculate this proportion, a hypothetical time origin was considered for each decade, and the Probit model was employed to calculate the probability of menarche at each age. Results: Findings indicate that approximately 10% of Iranian girls experienced menarche before age 11, while 90% reached menarche by age 14.89, with a median age of 12.89 yr. A significant downward trend in the age at menarche was observed; girls born between 1946-1957 experienced significantly later menarche compared to those born in the 1958-1969 and 1970-1981 cohorts at the 10 Conclusion: The observed downward trend in menarche age in central Iran aligns with results from similar studies in developing countries. This declining trend has historically been attributed to lifestyle-related variables. Today, this decreasing trend (acceleration of puberty) can be attributed to poor nutritional habits, sedentary lifestyles, or a physiological response to increased physical and mental stress.
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