menarche

Sex hormones play role in development of autoimmune diseases such as multiple sclerosis (MS). In our previous systematic review, we included three studies and reported the pooled odds ratio (OR) for increasing 1 year of age at menarche and risk of MS as 0.88. So, we designed this systematic review and meta-analysis to estimate the pooled mean age at menarche difference between women with MS and controls and also update the odds of developing MS by increasing age at menarche.

We performed a comprehensive systematic search on PubMed, Scopus, EMBASE, and Web of Science on July 1st, 2023. Also, grey literature including conference abstracts and references of the references were investigated to find potentially relevant articles.

A total 634 records were retrieved by systematic search. Also, one relevant record was identified from grey literature. After deduplication, 331 articles were remained for title/abstract screening and of those, 29 full-texts were evaluated. Finally, 15 studies were included in final analysis. The SMDs of age at menarche (control group – case group) ranged between -0.18 and 1.41. The pooled SMD of age at menarche (controls-cases) was 0.17 (95% CI: 0.09-0.25) (I2=85.1%, p<0.001). OR for age at menarche and risk of MS ranged between 0.8 and 1.76, and the pooled OR for increasing 1 year of age at menarche estimated as 0.92(95% CI: 0.89-0.94) (I2=41.6%, P=0.07).

The results of this systematic review show that the mean age at menarche is higher in controls than women with MS, and the risk of MS decreases by increasing age at menarche

The impact of artificial light exposure on human health has garnered significant attention in recent years. In particular, its effects on reproductive health have raised concerns. Given that the onset of menarche serves as a crucial indicator of reproductive maturity, understanding the implications of artificial light exposure becomes paramount. Age of menarche onset occurs relatively earlier in urban females than females raised in rural areas. Besides the decline in age of menarche onset, exposure to artificial light may contribute to impairment in reproductive hormones, particularly gonadotropins, by disrupting rhythms of reproductive hormones, modulating stress hormones and kisspeptin productions, and causing body weight changes. This drastic environmentally induced change may increase the proportion of teenage pregnancies, unfulfilled childhood dreams, depression, and ill-prepared marriages, thus creating a potential need for public health intervention. Due to limited studies and often lack of longitudinal data, a significant knowledge gap exists in unraveling the potential mechanism involved in alteration of these physiologic processes. The purpose of the current review was to elucidate the intricate interplay between environmental factors, cultural practices, and biological processes within indigenous communities. By meticulously examining the multifaceted influences of artificial light, including its prevalence and varying intensity based on geographical locations and light pollution levels, this study aimed to provide scholarly insights in-to the pathophysiologic mechanisms underlying the observed changes. The findings of this inquiry will also inform evidence-based strategies and interventions aimed at safeguarding the reproductive well-being of indigenous populations amidst the escalating challenges posed by artificial light exposure.

Adolescents experience rapid height growth during puberty, which eventually slows down and ceases due to epiphyseal senescence. Menarche marks the final stage of puberty and often raises concerns about the cessation of height growth.

This study aims to examine post-menarche height growth and identify the factors associated with it.

This retrospective cross-sectional study included adolescent females who visited pediatric endocrinology clinics in Hamadan between 2001 and 2018 and had a minimum follow-up period of three years. Data extracted from patients' medical records included demographic details, birth weight, birth order, height, weight, Body Mass Index (BMI), and stages of thelarche and pubarche. Data analysis was conducted using SPSS version 26.

The medical records of 91 girls were evaluated. The mean age of menarche was 11.93 ± 1.27 years. On average, the participants grew 7.98 ± 3.47 cm in height within three years after menarche. The study revealed a significant inverse correlation between post-menarche height growth and both the age at menarche and height at the onset of menarche. No correlation between height growth and other variables was observed.

Post-menarche height growth was negatively correlated with height and age at menarche. However, there is limited research on post-menarche height growth in Iranian girls, highlighting the need for further studies.

Epidemiologic studies have shown a discrepancy between overweight and puberty processes. This cross-sectional study was aimed to clarify these associations in the Iranian girl population. A total of 1300 girls aged 11-15 years were randomly selected from Mashhad, in the northeast of Iran, using a multi-stage cluster sampling method. The demographic data were collected and weight, height, and waist circumference (WC) were measured, then Body Mass Index (BMI) and Waist-to-Hip ratio were calculated. Overweight and obesity were defined based on WHO reference data. Central obesity was defined as ≥90th percentile of WC. Linear regression an unconditional binary logistic regression were performed to investigate the association between sociodemographic parameters and age at menarche in months, puberty categories, and menarche age groups (<12 vs. ≥12 years) respectively. The prevalence of overweight, obesity, and abdominal fat distribution were 11.5%, 10.3%, and 10.5% respectively. Menarche was experienced by 63% of subjects at the mean age of 12.24±0.98 years. Regression tests revealed that the odds of menarche occurrence at the age of 12 or more was significantly lower in girls with higher BMI (OR: 0.31, 95%CI: 0.22-0.43) than their leaner counterparts (P< 0.001). The findings suggest that being overweight or obese is a possible predictor of experiencing menarche at a younger age.

Background &  Menarche is an important stage in the development of girls which can predict the adolescent’s puberty process and fertility onset. The changes in menstrual cycle have health consequences not only in adolescence but also over the life-course. Childhood obesity as a common health problem has been observed in both developed and developing countries, and its prevalence is continuing to increase. The aim of this study was to identify menstrual patterns and related disorders and also to investigate the relationship between menarche age, menstrual disorders, and (BMI) in high school girls in Urmia.Materials &  In this cross-sectional study, 716 adolescent girls aged 14-18 years were selected with multistage sampling from high schools of Urmia (Sept 2012 to Dec 2013). Participants completed the questionnaire of menstrual pattern characteristics including age at menarche, menstrual cycle length, dysmenorrhea, and the need for pain relief. BMI percentile was calculated and obesity was determined using the CDC’s 2000 BMI-for-age growth charts. The results showed that the average of age, BMI, and menarche age were: 15.66±1.019 year, 22.05±3.91 kg/m2 and 12.87±0.98 year, respectively. The prevalence of overweight and obesity were 13.7% and 8.4%, respectively. A large majority of the subjects (76.1%) had a normal, healthy weight. There was a significant association between BMI and the duration of flow, menarche age, menstruation flow, and pain severity (P<0.05). Based on the results, planning and intervention for decreasing the BMI in high school girls can help reduce menstrual disorders. Future studies are required to confirm and complete our results.

The time interval between the age at menarche and regulation of menstrual cycles (menstrual cycle developmental trajectory) is considered an indicator of the reproductive system's function later in life. This study aimed to summarize the factors affecting this trajectory.

A comprehensive literature search in PubMed, Scopus, Google Scholar, and Web of Science was performed to identify studies investigating factors influencing the regularity of the menstrual cycle in adolescents.

The interval between menarche and the onset of the regular menstrual cycle in adolescent girls may vary from several months to several years. Several factors, including genetic, race/ethnicity, intrauterine situation, social factors, geographical factors, lifestyle, and chronic diseases, are considered the predisposing factors for the trajectory.

Age at menarche and the onset of regular menstrual cycles are directly and indirectly influenced by several genetic, environmental, and lifestyle factors. Understanding these factors may improve our practice in managing irregular menstrual cycles that commonly happen in the first years after menarche.

Due to the increased effect of environmental factors on the age of menarche and the correlation between the mothers’ and daughters’ age of menarche, we aimed at performing a meta-analysis to compare the mean age of menarche between the mothers and their daughters, examining the correlation between them. This systematic review was conducted to determine the heritability of daughters’ age of menarche. In this systematic review and meta-analysis, a complete search was carried out in PubMed, Scopus, Google Scholar, Web of Science, Science Direct, and CINAHL electronic databases in English with no time limitation. A meta-regression analysis was then performed to evaluate the effect of age and sample size. 13 studies with a total sample size of 9719 for calculating the standardized mean difference and 15 articles with a total sample size of 8840, related to the research objectives, were analyzed in this meta-analysis. The pooled mean of the daughters’ age of menarche was 12.62 yrs. (95% CI: 12.37 – 12.87) and that of the mothers’ age of menarche was 13.58 yrs. (95% CI: 13.31 – 13.81). The standardized mean difference between the mothers’ and daughters’ ages of menarche was -0.72 (CI: -0.99 to -0.44). The results of the meta-analysis revealed that, overall, there is a significant positive correlation between the mothers’ and daughters’ ages of menarche (r=0.27 [CI 95%: 0.17-0.36]). The daughters’ ages of menarche were positively correlated to those of their mothers, but the other environmental factors that may affect this decreasing trend should also be taken into account. Health policy-makers should plan to identify strong predictors, which can be effective in reducing the age of menarche.

Menarche is a sign of puberty and the beginning of ovarian and other endocrine functions relating to reproduction. It is an important event demonstrating the end of childhood and the start of reproductive years for each woman that is preceded by the complex process of some hormonal changes in the puberty period. Moreover, it is an important clinical indicator of girls’ physical, nutritional, and reproductive health. Early age at menarche, as the onset of menstrual periods in girls, has a substantial effect on their physical and sexual health and is related to the increased risks of unfavorable health outcomes. Further, menarche appears to be associated with several risk factors of emergent chronic disease. In recent decades, the age at menarche has shown a gradual decline from 16-17 years to less than 13 years. Evidence indicates that childhood obesity is related to earlier menarche. Finally, this change may be partially explained by the global epidemic of obesity.

Reduced age at menarche is an important health indicator for women and may be associated with complications such as an increased risk of asthma, breast cancer, ovarian cancer, type 2 diabetes. We aimed to examine the factors related to the age at menarche in Iran.

In this systematic review and meta-analysis, an advanced search with no time restriction was conducted in online databases such as the Web of Science, Embase, Medline, Scopus, and Persian databases of SID and Magiran, as well as the Google Scholar search engine, until the end of 2019. The publication heterogeneity and bias of the extracted studies were evaluated by the Q test and Begg’s test, respectively.

In this study, 12 articles with a total sample size of 17672 were included. Based on the findings of these studies, the body mass index (BMI), the mother’s age at menarche, physical activity, nutrition, and socioeconomic status were correlated with the age at menarche for Iranian girls. A negative correlation was found between BMI (r=-0.07), and socioeconomic status (r=-0.57) with the age at menarche (P<0.05). A positive correlation existed between the girl's age at menarche and that of the mother (r=0.42, P<0.05). Moreover, correlation was weak and positive between the age at menarche and physical activity (r=0.14, P<0.05). The quantitative results of the studies were incomplete to establish a relationship between nutrition and age at menarche.

Due to the effects of numerous factors on the age at menarche, it is suggested that longitudinal studies be conducted to investigate the role of all the known factors, especially environmental factors, on the age at menarche.

Age at menarche is the key indicator of puberty in females and the reflector of populations’ health that different hereditary and environmental factors can affect it. This study was conducted to determine the age at menarche and its relationship with body mass index (BMI) and demographic factors among students of Qaen, Eastern Iran. This cross-sectional study was conducted on 400, 10 - 16-year-old students of Qaen located at the East of Iran, in 2016. The participants were selected by the random multistage sampling of students in elementary and secondary schools that were eligible to participate in the study. Data collection was carried out through interviews and a checklist including demographic and menarche information as well as height and weight measurements in schools. The data were analyzed using SPSS V. 18 by Pearson’s correlation, t-test, and multiple linear regression. The mean age of students was 13.86 ± 1.10 years, mean BMI was 20.38 ± 2.72 kg/m2 and the mean age at menarche was 12.78 ± 1.23 (95% CI: 12.66 - 12.90) years. There was an inverse correlation between the age at menarche and BMI (r = -0.123, P = 0.014) while the height (r = 0.195, P = 0.0001), maternal age (r = 0.223, P = 0.0001), and sleep duration (r = 0.156, P = 0.002) were directly related to age at menarche. No significant relationship existed between age at menarche and weight of students (P = 0.86). The mean age at menarche of students was as average as Iranian studies. Lower age at menarche was significantly correlated with higher BMI.

A neoplasm, also referred to as a tumor, is an abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of normal tissue and remains in the same excessive manner even after removal of the stimuli which evoked the changes. Tumors may be either benign or malignant. Benign tumors remain localized and are amenable to surgical removal, whereas malignant tumors, i.e. cancerous ones, adhere to any part in an obstinate manner, often invade surrounding tissue, and metastasize to distinct sites. Breast cancer occupies second place as the most occurring cancer in terms of incidence. Breast cancer is a heterogenous cancer, mostly linked with reproductive and hormonal factors in its occurrence. Nulliparous, younger age at menarche, early age pregnancy, older age at first live birth, late menopause, prolonged interval between menarche and first pregnancy, repeated abortions, first pregnancy after 35 years, and no/less breastfeeding are major risk factors for breast malignancies. Recent studies have shown that the implications of reproductive and hormonal factors in patients with breast cancer are associated mostly with BRCA1 (breast cancer gene 1) and BRCA2 (breast cancer gene 2) gene mutations.

Our aim was to determine the association between age at menarche (AAM) and breast cancer adjusted for recall bias (misclassification) in AAM. We have used data provided from a case-control study conducted in Iran from 2005 to 2009. The cases and controls were frequency matched based on 5-year age groups and region of residence. First, logistic regression was conducted to estimate the odds ratio (OR) and second, Bayesian analysis was applied to estimate the ORs adjusted for misclassification. The study was conducted on 880 cases and 998 controls. In the assumption of no correction for recall bias on self-reported AAM, the OR was 1.36 (95% Credible Interval (0.98, 1.90). Based on a sensitivity value = 71% and a specificity value = 81% (the indices about the ratio of true recall of AAM) for the case and control groups (as the first scenario), the AAM ≤ 12 years of age was associated with a lower OR for breast cancer by 1.23 (95% Credible Interval: 0.50, 3.13). In the other scenario, with consideration of 100% sensitivity and specificity of self- reported AAM in the case group, and 71% and 81% sensitivity and specificity of the item in the control group, the related OR between breast cancer and AAM was found increased to 2.96 (95% Credible Interval: 0.75, 7.66). After adjustment for misclassification related to recall bias, this study provides evidence that the self-reported mode of AAM has a moderate impact on calculation of the OR.

The age of menarche can be different among girls based on region, ethnic, and some individual factors such as body mass index (BMI). Little is known about the menarche age in Kurdish girls. This study was conducted to determine the menarche age and its association to BMI and socioeconomic status among Kurdish schoolgirls. This was a cross-sectional study conducted on 400 schoolgirls from different secondary and high schools in Sanandaj, northwest of Iran. Multi stage sampling was used to select the study samples. Data were collected using a checklist, which included demographic information and other variables under investigation. SPSS version 20 was used for data analysis. Independent sample t-test, one-way ANOVA, and logistic regression were used for data analysis. The significance level of the tests was considered to be 0.05. The mean and standard deviation (SD) of menarche age was 12.87 ± 1.17 years. About 60.3% of girls had normal BMI and 31%, 6.8%, and 2% of them were underweight, overweight, and obese, respectively. There was a significant relationship between higher BMI (P = 0.02) and menarche age. Based on multivariate analysis, the chance of early menarche in children with higher BMI (≥ 25) was significantly 3.57 times higher than others (P = 0.004). There was no significant relationship between socioeconomic status, physical activity, and birth season, attitude towards menarche, nutritional status, and number of brothers with age of menarche. The results showed a significant relationship between menarche age and BMI. The age of menarche in our region was also different compared to other regions of the globe. The findings of the present study can be used by health policy makers for planning and conducting the interventional programs related to menarche in girls.

In this study, we assessed the secular trends and socioeconomic differentials in menarcheal age among women aged 25-64 year.
Using the 5th Korea National Health and Nutrition Examination Survey (KNHANES, 2010-2012), bivariate analysis and one-way analysis of variance were used to test the statistical differences between age groups.
The mean age at menarche was 14.3 yr with a steep decrease in the younger cohort: from 15.9 yr in 1951-1955 to 13.1 yr in 1986-1990. Height as a proxy marker for early nutrition showed an inverse relationship with menarcheal age. The earlier menarcheal age patterns in women of higher socioeconomic position were observed according to one's education, monthly family income, occupation, region (urban vs. rural), and parental education.
This result suggests a fast and ongoing trend in age at menarche and the socioeconomic discrepancy among Korean women in the last four decades.

Dysmenorrhea is one of the most common gynecological problems. This study aimed to determine the relationship between age at menarche and painful menstruation among female students of Shiraz schools.
This cross sectional study was conducted on 2000 female students. For data collection, a researcher-made questionnaire was applied. Data were analyzed using statistical tests in SPSS version 21.
About 69.3% of the participants had experienced at least 1 episode of menstrual bleeding. Among postmenarcheal subjects, 77.7% had dysmenorrhea, while 22.3% did not. There was no significant relationship between age at menarche and dysmenorrhea (P = 0.15). However, there was a significant relationship between the onset of dysmenorrhea and postmenarche years (P Although two-thirds of students suffered from primary dysmenorrhea, no significant relationship was found with age at menarche. Therefore, the high prevalence of dysmenorrhea among students calls for proper counseling and management.