Age at menarche of schoolgirls in Maputo,Mozambique

Age at menarche was analysed in 753 Mozambican schoolgirls taking part in across-sectional anthropometric study in Maputo, Mozambique, in 2000. The probit analysis of the status quo data yielded an median age at menarche of 13.20 +/- 1.18 years. The retrospective method was applied only to recall data of the 396 post-menarcheal girls and it yielded an average of 13.91 +/- 1.29 years. Mean age at menarche in girls living in the urban centre of Maputo was 13.35 and 12.96 years, for recall age and probit analysis, respectively, and 14.51 and 13.68 years for girls living in the slums surrounding the centre. The differences in age at menarche, calculated by recall method, between girls from central Maputo and girls from the slums were statistically significant (p = 0.000). Parent's educational level also revealed a significant effect on age at menarche. Girls whose parents had a lower educational level showed a later age at menarche. For the size of the family, girls who were later borne had a higher age at menarche. In the 1960s, the age at menarche was 13.55 and 13.83 years in urban and rural girls, respectively. In this study, we found a lack of decrease in the mean age at menarche (13.9 years), which could be due to the poor living conditions in Mozambique between 1960 and 2000 as a result of the civil war from 1976 to 1990. Despite the economic growth of the country in the last decade, Mozambique is still in the group of the poorest countries in the world; in spite of this fact, the mean menarcheal age in these girls are amongst the lowest values presented for African countries.     

Secular change in age at menarche in rural Oaxaca, southern Mexico: 1968--2000

OBJECTIVE: To evaluate secular change in the age at menarche between 1978 and 2000 in residents of a rural Zapotec-speaking community in Oaxaca, southern Mexico, using status quo and retrospective methods. MATERIALS AND METHODS: Status quo menarcheal status of girls 9-18 years of age in 1978 (n= 101) and 2000 (n=238) and retrospective ages at menarche of adult women 19+ years of age in 1978 (n = 228) and 2000 (n = 246) were obtained via interview. Probit analysis was used to estimate median ages at menarche and 95% confidence intervals (CI) for the status quo data. Analysis of variance and linear regression was used to compare the retrospective data across surveys. RESULTS: The median ages at menarche of adolescents are 14.8+/-1.2 years (0.24 year, 95% CI 14.2-15.4 years) in 1978 and 13.0+/-1.0 years (0.10 year, 95% CI 12.7-13.3 years) in 2000. Age at menarche has declined by 1.8 years over about 23 years, 0.78 year/decade (95% CI = 0.65-0.91 year/decade). Recalled ages at menarche do not differ by age group in the 1978 survey, but differ significantly by age group in the 2000 survey (p <0.001). Within the 2000 survey, the two youngest age groups (< 29, 30-39 years) do not differ, but attain menarche earlier than women in the four older age groups (p < 0.05), who do not differ from each other in age at menarche. The estimated rates of secular decline in age at menarche in adult women vary between 0.38 and 0.42 years/decade (0.26-0.56 year/decade). CONCLUSIONS: There is a major secular decline in the age at menarche of adolescent girls and young adult women between 1978 and 2000. The estimated rate of decline in adult women is about one-half of that in adolescent girls. The secular decline in age at menarche is consistent with corresponding secular gains height, sitting height and estimated leg length of children and adolescents in the community; corresponding secular gains are smaller in young adults 19-29 years.     

Menarcheal age in central Italy

Estimates of menarcheal age in girls in central Italy based on the status quo and recall methods are compared. Results obtained by the two methods differ significantly in that the recall method underestimates age of menarche even though utmost care was used in data collection (province of Rome: status quo 12.44, retrospective 11.84; Molise: status quo 12.51, retrospective 12.12). Positive and negative aspects of the two methods are discussed. © 1994 Wiley-Liss, Inc.     

Secular shift in menarcheal age of Patiala (India) schoolgirls between 1974 and 1986

The secular shift between 1974 and 1986 in the menarcheal age of Patiala schoolgirls has been explored. A total of 946 girls of higher and lower social classes (type of school being the criterion) were surveyed, out of which 421 were menstruating at the time of investigations. The median ages at menarche (by probits) of higher social class girls were 12.90 +/- 0.64 years in 1974 and 12.54 +/- 0.13 years in 1986, and of lower social class girls 14.40 +/- 0.47 years in 1974 and 13.65 +/- 0.18 years in 1986. The secular shift per decade in higher and lower social class girls is 0.30 years and 0.63 years, respectively. The social class differences during this period in menarcheal age have decreased.     

The age of menarche in Nigerian urban school girls

In March and April 1978, a sample of 1365 girls from three secondary schools within and near Enugu (capital of Anambra State of Nigeria) were interviewed regarding date of birth and menstrual status. Using probit analysis, the mean age at menarche was 13.54 +/- 0.07 years, implying, when compared with earlier studies, a rate of decline in the average menarcheal age of about four months per decade. Significant differences were observed in the menarcheal ages of the girls with respect to their geographical residence and the occupation of their fathers. The results obtained in the study are similar to those reported by Oduntan et al. (1976) for south-western Nigeria, and they lend support to the proposition that improvements in nutrition and the elimination of infectious diseases (characteristic associated with socioeconomic development) tend to reduce the average menarcheal age.     

Age of menarche in Oaxaca, Mexico, schoolgirls, with comparative data for other areas of Mexico

Status quo menarcheal information was collected for a mixed urban colonia and rural sample of 315 girls in the Valley of Oaxaca, Mexico. Comparative status quo data for girls from four major urban centres in Mexico, and for a rural sample were also analysed. Median age at menarche (estimated by probit analysis) for Oaxaca girls was 14.27 +/- 0.20 years, about 0.5 year later than that for the rural sample from Tampico-Altamira, Tamaulipas (13.79 +/- 0.20 years), and approximately 1.5 years later than that for girls from the four urban centres in Mexico (12.55 +/- 0.10, 12.61 +/- 0.08, 12.75 +/- 0.10, 12.76 +/- 0.07 years). The timing of menarche in Oaxaca girls is similar to that for rural Mayans in Guatemala. Ages at menarche for urban Mexican girls are somewhat lower than those for girls of North-west European ancestry and of North American girls of European ancestry.     

Changes in menarcheal age in girls exposed to war conditions

The purpose of this study was to assess changes in mean menarcheal age of girls in the city of Šibenik in the period from mid-1980s to the mid-1990s. Šibenik is a Dalmatian town which was exposed to hard war conditions in 1991–1995. Menarcheal status of Šibenik girls was surveyed three times, in 1981, 1985, and 1996, and included 720, 1,207, and 1,680 girls, respectively, ages 9.5–16.5 years. Mean menarcheal age was estimated by the status quo method and application of probit analysis. Results show a slight decrease in menarcheal age from 1981 to 1985 (from 12.97 ± 0.06 years to 12.87 ± 0.05), and then a significant increase from 12.87 ± 0.05 years in 1985 to 13.13 ± 0.10 years in 1996. The increase in mean menarcheal age occurred in all socioeconomic groups based on parental occupation and number of siblings. In the group of girls whose homes were damaged during war, menarche occurred at an average of 13.53 ± 0.14 years, while those who lost a family member experienced menarche at an older mean age, 13.76 ± 0.27 years. However, when the girls who experienced personal tragedies were excluded the onset of menarche was still later than in girls surveyed in the earlier periods. The results suggest that the general reversal in the secular trend of menarcheal age in Šibenik girls can be attributed to persistent psychological pressures and uncertainties associated with conditions of war. Am. J. Hum. Biol. 12:503–508, 2000. © 2000 Wiley-Liss, Inc.     

Age at menarche in Coimbra (Portugal) school girls: a note on the secular changes

The age at menarche and several menstrual symptoms were reported by 516 Portuguese school girls who took part in a cross-sectional anthropometric study in Coimbra, Portugal. The mean ages of menarche calculated using the recall method and also using probit analysis were 12.53 +/-1.27 and 12.03 +/- 1.26 years, respectively. Parents'educational level, place of residence and size of the family did not have any significant effect on the mean age at menarche in this sample of adolescents. The order of birth was the only variable that indicated a significative effect: the first borns reported a lower mean age at menarche (12.34 years) than the later borns (12.6 years). In this sample, 47% of the girls had a cycle length of >or = 29 days, 23.4% had irregular cycles, 59% reported that the duration of bleeding was 3-5 days and the majority, 49%, did not report any pain during the bleeding days. However, 14.3% and 24.45% reported severe and medium pain. The age at menarche has declined from 15.0 (girls born in 1880-1890) to 12.03 (girls born in 1970-1980) years in the Portuguese population. This decrease in age, and also the lack of influence of the family characteristics, appear as a result of the great improvements in the social and economic living conditions that occurred in Portugal, especially after the 1970s. These improvements are mainly related to better nutrition and better health care along with many other environmental factors.     

Age at menarche as an indicator of the socioeconomic situation of rural girls in Poland in 1967, 1977, and 1987

Village girls, 9.5–18.5 years of age, inhabiting various regions of Poland, were surveyed in 1967 (n = 7,886), 1977 (n = 7,771), and 1987 (n = 11,479). Based on the source of income of the families, three groups were identified: farmers, farmer-workers, and nonfarmers. The girls were also divided on the basis of the number of children in the family and education of their fathers. In all three surveys, the earliest age at menarche was observed in girls from the nonfarmer group and the latest in girls from the farmer group. In 1987 the ages at menarche were 13.27 ± 0.03 years and 13.58 ± 0.04 years, respectively. The rapid acceleration of menarcheal age (0.64 year) between 1967 and 1977 was halted, and perhaps, reversed from 1977 to 1987 (?0.06 year), reflecting the severe social and economic crisis in Poland. The later menarcheal ages observed in the last decade occur mainly among girls from families with four and five children. Girls from better educated rural families were more affected by the crisis than girls from families in which fathers have only an elementary or vocational training education. © 1995 Wiley-Liss, Inc.     

Trend of Menarcheal Age among Korean Girls

BackgroundMenarcheal age has been decreasing worldwide. However, few recent studies have observed trends in menarcheal age in larger populations, and the cutoff age for early menarche remains unclear. Therefore, we aimed to analyze recent trends of menarcheal age and to determine the cutoff age of early menarche based on nationally representative data.MethodsWe conducted a cross-sectional study of 351,006 Korean girls aged 12–18 years who were born in 1988–2003 based on the data of the 2006–2015 Korea Youth Risk Behavior Survey. We identified the distribution of age at menarche using the complex sample Cox regression model. Trends in the prevalence of early menarche were determined using the complex sample linear model.ResultsNinety-five percent of all the participants reported they had experienced menarche. The mean menarcheal age was 13.0 years (95% confidence intervals [CIs], 12.92–13.04) for girls born in 1988 and decreased to 12.6 years (95% CI, 12.54–12.61) for girls born in 2003. The cutoff age (the 3rd percentile value) for early menarche was 10.5 years during the study period. The prevalence of early menarche significantly increased from 1.8% in 2006 to 3.2% in 2015 (P-for-trend < 0.001). Downward trends of menarcheal age were noted across all body mass index groups, and this trend was most prominent in the obese group.ConclusionWe reported an ongoing downward trend in menarcheal age in Korean girls born in 1988–2003, decreasing by 0.4 years over the 15 years.     

Sexual maturation in Turkish girls

Ages of attainment of successive puberty stages of the breast, public hair and axillary hair and of menarche were established in a cross-sectional study of 1468 Turkish school girls in Istanbul. The subjects were grouped into four socioeconomic classes. Onset of secondary sexual characteristics and of menarche in the highest socioeconomic class were early as compared to other population groups. Mean ages of attainment for the initial stage of breast, pubic hair and axillary hair development were 9.8, 10.4 and 10.8 years respectively in this group. Mean menarcheal age was 12.36 +/- 0.01 years. All stages of breast, pubic hair and axillary hair and also menarche consistently occurred later in the lower socioeconomic classes as compared with the higher. The time intervals from onset to completion of secondary sexual characteristics were comparable to those reported for European girls for pubic and axillary hair development, but relatively longer for the development of the breast. They differed little between the socioeconomic classes.     

Age at menarche based on recall information

Censored likelihood methods which use recalled dates yield accurate estimates of the age at menarche in an urban population of black adolescent girls. The mean age at menarche is 12.44 (SE 0.08) years for a sample of 272 black adolescents in Philadelphia, PA. The methodology we describe is more efficient than logit or probit methods, which are not designed to utilize recall information. Alternative methods which use recall are biased if subject memory is influenced by length of time since menarche. Our methods also provide information on the nature of subject recall that may be useful in further analysis.     

The relation of menarcheal age to anthropometric profiles in Korean girls

The aim of this study was to represent the trend of early menarche and to assess the association of age at menarche with anthropometric profiles of Korean children and adolescents. A cross sectional survey was conducted with 13,371 girls aged 10 to 18 yr, recruited nationwide from April, 2005 to March, 2006. Height, weight and waist circumference of the subjects were measured; and the subjects self-reported their ages at menarche. We found that the menarcheal girls were taller (P<0.05 for the girls between 10 and 14 yr) and heavier (P<0.05 for the girls between 10 and 18 yr) than non-menarcheal ones. Menarcheal girls also showed higher body mass index (BMI), and greater waist circumference than non-menarcheal ones. Significant differences were represented according to the age at menarche in terms of BMI, waist circumference, % body fat mass, waist hip ratio and neck circumference as well as height and weight (P<0.05). In conclusion, girls who matured early were taller and heavier in early adolescence than those who matured later.     

Age at menarche in Iran

BACKGROUND: Age at menarche and its potential associated factors are reported for 1862 Shiraz (Southern Iran) secondary school girls taking part in a cross-sectional survey selected from the four educational districts of the city. METHODS: Probit analysis was used to estimate age at menarche, principal component analysis (PCA) was applied to analyse socio-economic status (SES). Body mass index (BMI) was used as an indicator of nutrition. RESULTS: Mean +/- SD age at menarche was 12.91 +/- 1.23 years (95% CI: 12.84-12.97). Of all subjects, 33.7% first menstruated in summer. The highest mean age at menarche was 13.01 years in winter. Stress, anxiety and discomfort was seen among 70.3% of subjects at menarche indicating total or partial ignorance of the menstruation phenomenon. Age at menarche decreased as SES improved. Menarcheal age was delayed for underweight subjects. CONCLUSIONS: It is concluded that BMI and SES had the most significant effects on variation of menarcheal age in a unified statistical model. However, their interaction was found to be not statistically significant.     

Body size and fatness in young adults in relation to age at menarche

The relationships among age at menarche, body size, and body composition were considered in university students surveyed in 1970 (n = 342) and 1987 (n = 109). Recalled ages at menarche, stature, weight, and the triceps skinfold thickness were measured. Subjects ranged in age from 17.5 to 22.5 years in both surveys and were divided into four categories by age at menarche: before 12 years, 12.0 through 12.99 years, 13.0 through 13.99 years, and older than 14 years. In both the 1970 and 1987 surveys, later maturers had significantly more linear physiques than those experiencing menarche earlier. Late maturers also showed a tendency to lower values for the body mass index (BMI) and triceps skinfold compared with early maturers. Comparative data for women of the same age from the Fels Longitudinal Study (n = 234) showed similar findings. Women who reached menarche at ages older than 14 years were significantly taller than women with menarcheal ages less than 13 years. Women with menarcheal ages younger than 12 years were significantly heavier and had higher BMIs than those from any older menarcheal category. They also had significantly thicker triceps skinfolds than those with menarcheal ages older than 14 years. © 1992 Wiley-Liss, Inc.     

Combined estrogen receptor alpha and estrogen receptor beta genotypes influence the age of menarche

BACKGROUND: Age at menarche has a strong genetic influence. We reported recently an association between the XbaI (351A-->C)and PvuII (397T-->C) polymorphisms of the estrogen receptor (ER)alpha gene with the age of menarche in Greek adolescents. In the present study, we examined whether ERbeta genotypes alone, or in combination with ERalpha genotypes, may also influence onset of menarche. METHODS: We performed genotyping for the single nucleotide polymorphisms 1730A-->G and 1082G-->A of the ERbeta gene and examined their association with the age of menarche in the same cohort of 145 Greek girls. We then looked for a possible effect of combined ERalpha and beta genotypes on the age of menarche. RESULTS: Menarche occurred 7 months later in girls with the AA genotype of the 1730A-->G polymorphism than in girls with the AG genotype (mean +/- SD: 13.23 +/- 1.24 versus 12.66 +/- 1.26 years, respectively; P = 0.005). The 1082G-->A polymorphism was not detected in any of the girls examined. A significant effect of combined ERalpha and beta genotypes was also apparent. Menarche occurred 11 months later in girls bearing the AA/TT,AA (ERalpha, ERbeta) genotypes compared with girls with the CC/CC,AG genotype (13.30 +/- 1.27 nersus 12.41 +/- 1.28 years; P = 0.042). The difference remained significant after adjusting for body mass index (P = 0.034). CONCLUSION: Combined ERalpha and ERbeta polymorphisms may influence the age of menarche.     

Menstrual patterns in adolescent Swiss girls: a longitudinal study

Menstrual patterns were studied longitudinally in 140 adolescent Swiss girls. The mean cycle length was 32.2 (S.D. 11.24) d in the first year after menarche, and 29.9 (S.D. 7.12) d in the sixth year after menarche. The values of the mean cycle length became essentially constant from the sixth post-menarcheal year, the chronological age of 20 y and the 36th post-menarcheal cycle. No association was found between cycle length and age at menarche. The menarcheal age of mothers and that of their daughters were significantly correlated with each other (r = 0.29, P less than 0.001). The most frequent cycles of 21-27 and 28-34 days constituted 64-81% of all cycles depending on post-menarcheal age. Short cycles (14-20 d), representing 2-6% of all cycles, were present in 14-31% of the girls; long cycles (35-41 d), constituting 10-16% of all cycles, occurred in 46-68% of the girls. The frequency of the long cycles tended to decrease at higher post-menarcheal ages. There were minimal changes in the duration of menstrual flow throughout the first six years after menarche. The mean duration was 5.4 (S.D. 1.72) d for the first year, and 5.1 (S.D. 1.33) d for the sixth year. The most frequent flow duration was 3-7 d, present in 88-94% of cycles. Prolonged bleeding tended to decrease with rising post-menarcheal and chronological age. The intensity of menstrual flow was mild in 11-16%, moderate in 62-78% and severe in 11-25% of the girls. The frequency of these three categories remained essentially unchanged during the first five post-menarcheal years.     

Allometric relationship between body size and peak VO2 relative to age at menarche

The present study examined allometric coefficients relating peak VO2 and body size relative to the time of menarche. Peak oxygen uptake (peak VO2) during exercise on a bicycle ergometer, stature and body mass were measured at annual intervals in a mixed-longitudinal sample of 40 active girls from 11 to 14 years of age. The girls were interviewed about their menarcheal status at each examination. The data were treated relative to the time before and after menarche: 2 years before (n = 18), 1 year before (n = 26), during the year of menarche (+/- 6 months, n = 32), 1 year after (n = 35) and 2 years after menarche (n = 22). Allometric coefficients were calculated for each of the five menarcheal groups based on logarithmic transformations of peak VO2 and body mass and peak VO2 and stature. The major axis of VO2 and body mass or stature (log transformed) was also calculated. This is the most appropriate slope for comparison with theoretical allometry coefficients. Mean peak VO2 increases from 2.1 +/- 0.19 L 2 years before menarche to 2.3 +/- 0.26 L 2 years after menarche. The slope of the major axis for body mass is always higher (0.508-0.926) than that for the allometric coefficient (0.323-0.591) in each of the menarcheal groups. The major axis slope and allometric coefficient are lowest between body mass and peak VO2 during the year of menarche. The slope of the major axis is below the theoretical allometric coefficients assuming geometric or elastic similarity, 2/3 or 3/4, before and at menarche and increases after menarche. Although the differences are not statistically significant, the results suggest that the relationship between body mass and peak VO2 at menarche is lower compared with relationships before and after this maturational landmark. Allometric coefficients for stature relative to peak VO2 show a similar pattern.     

Age at menarche in Peruvian girls at sea level and at high altitude: Effect of ethnic background and socioeconomic status

The objective of the present study was to determine median age at menarche using the status quo method and the independent effects of ethnic background and socioeconomic status on the age at menarche in Peruvian girls from two distinct levels at altitude: Lima (150 m) and Cerro de Pasco (4,340 m). The sample included 503 girls from Lima and 625 girls from Cerro de Pasco, ages 10–18 years. Ethnic background was determined by four parental surnames. Subjects were classified as Quechua when one or more surnames were from Quechua origin and Spanish when four surnames were from Spanish origin. Socioeconomic status was determined using a socioeconomic index score and subjects were classified as belonging to the middle-low, low, or very low class. Median age at menarche was calculated by survival analysis using the Life Table Method with a 95% Confidence Interval (CI). Among Quechua and Spanish girls, age at menarche occurred later at high altitude than at sea level. Median ages at menarche for the overall groups were 13.08 (12.91–13.25, 95% CI) years in Lima and 14.33 (14.17–14.48, 95% CI) years in Cerro de Pasco (P < 0.0001). Socioeconomic status had no significant effect on menarcheal age (P > 0.05). Controlling socioeconomic status in the design, median age at menarche was still higher at high altitude than at sea level (P < 0.05). After logistic regression analysis, an effect on age at menarche of chronological age and place of residence was observed, but not by ethnic background, socioeconomic status and not by interactions of age and place of residence, age and socioeconomic status, place of residence and socioeconomic status, place of residence and ethnic background, or socioeconomic status and ethnic background. Thus later age at menarche observed in girls at high altitude is not due the differences in ethnicity or socioeconomic status. © 1996 Wiley-Liss, Inc.     

Menarcheal age in Turkey: Secular trend and socio-demographic correlates

Background: Menarche is an important indicator for assessing the developmental status of pubertal girls. Despite its importance, there is no nationwide information on menarcheal age in Turkey.

Aim: This paper is the first attempt to examine age at menarche for Turkey as a whole. The aim is to present the secular trend of menarcheal age and variations across different socio-demographic groups.

Methods: Data were employed from the Turkey Demographic and Health Survey, 2008. Mean menarcheal ages were estimated for birth cohorts and socio-demographic sub-groups. The pace of decline in menarcheal age has been estimated using multiple linear regression analysis, controlling for year of birth and other variables.

Results: Mean age at menarche was estimated as 13.30 (95% CI = 13.26–13.35). It was estimated as 13.17 years (95% CI 12.95–13.38) for the youngest birth cohort (1989–1993), as opposed to 13.44 (95% CI 13.37–13.52) years for the cohort born in 1959–1968.

Conclusion: Regression analysis indicated a decrease of 1.44 months per decade, providing evidence of a secular trend in menarcheal age in Turkey. Further results suggested childhood place of residence, education, welfare status and number of siblings to be significantly associated with menarcheal age.