International Journal of
Reproductive Biomedicine
Mon, Nov 9, 2026
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Volume 24, Issue 6 (June 2026)
Int J Reprod BioMed. 2026, 24(6): 527-536 |
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Ethics code: IR.SSU.SPH.REC.1401.134
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Jambarsang S, Sefidkar R, Yoshany N, Khodayarian M. Secular trends in menarche age among Iranian girls: Probit analysis on cross-sectional data of Persian (Shahedieh) cohort. Int J Reprod BioMed. 2026; 24 (6) :527-536
URL: http://ijrm.ir/article-1-3852-en.html
URL: http://ijrm.ir/article-1-3852-en.html
1- Center for Healthcare Data Modeling, Departments of Biostatistics and Epidemiology, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. & Clinical Research Development Center, Shahid Sadoughi Hospital, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
2- Center for Healthcare Data Modeling, Departments of Biostatistics and Epidemiology, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
3- Department of Health Education and Health Promotion, Social Determinants of Health Research Center, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
4- Department of Health Education and Health Promotion, Social Determinants of Health Research Center, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. ,khodayarian@ssu.ac.ir
2- Center for Healthcare Data Modeling, Departments of Biostatistics and Epidemiology, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
3- Department of Health Education and Health Promotion, Social Determinants of Health Research Center, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
4- Department of Health Education and Health Promotion, Social Determinants of Health Research Center, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. ,
Abstract: (443 Views)
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 10th, 25th, 50th, and 75th percentiles.
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.
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 10th, 25th, 50th, and 75th percentiles.
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.
Type of Study: Original Article |
Subject:
Reproductive Epidemiology
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