Physiological maturation,reproductive patterns,and female fecundability in a traditional Moroccan population (Amizmiz,Marrakech)

The interaction between age at menarche, adolescent motherhood, and subfecundity were evaluated in 496 Moroccan women 25–54 years of age from the province of Marrakech. Since this population is characterized by later sexual maturation and early marriage, significantly increased subfecundity, measured by the waiting time to first live birth and the incidence of fetal loss, was expected. Menstrual age was defined as the difference between age at marriage and age at menarche. Social access to reproduction was conditioned by age at menarche: early maturers married at a younger age, while late maturers had a significantly shorter menstrual age despite the fact that married at a significantly older age. Although there was a tendency for late maturers to have longer waiting times and more fetal loss, there were no significant differences for either variable according to menarcheal age. Women with a shorter menstrual age became pregnant within the first year after marriage significantly less frequently than women with a greater menstrual age, but did not experience a greater occurrence of fetal loss during their reproductive life. The results indirectly support the hypothesis that the regularity of ovarian function is similar among populations independent of the timing of menarche. © 1993 Wiley-Liss, Inc.     

Age at puberty in relation to age at marriage and parenthood: A national longitudinal study

A longitudinal study of a British cohort has collected information on puberty, judged by menarcheal age for the girls and the pubertal stage of the boys at age 14 3/4. This information has now been related to the ages at which these young people married and became parents. For the young men there was evidence of a direct relationship between degree of sexual maturity at age 14 3/4 and their ages at entry into marriage and fatherhood. For the young women, if pregnancy did not intervene between menarche and marriage, there was evidence of a direct relationship between menarcheal age and marriage age. But there was no evidence that these earlier-maturing young women became mothers at earlier ages than later maturers. This arose through the later-maturing young women having shorter first birth intervals than the earlier maturers. Premarital conceptions were also more prevalent amongst the later maturers.     

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.     

Age at menarche in relation to adult body size and physique

The relationship of early and late menarche with adult body dimensions has been studied on a sample of 147 young adult women drawn from an urban Punjabi population of Chandigarh and Ludhiana. The results indicate that girls with early menarche (age 10 to 11) have significantly smaller skeletal dimensions (both longitudinal and transverse) and more subcutaneous fat than those with average or late menarche. The girls with late menarche have on average more height for weight than early maturers. Results indicate that there is a biological determinant of the observed association between menarcheal age and fatness and adult body size.     

Age at menarche in relation to adult body size and physique

The relationship of early and late menarche with adult body dimensions has been studied on a sample of 147 young adult women drawn from an urban Punjabi population of Chandigarh and Ludhiana. The results indicate that girls with early menarche (age 10 to 11) have significantly smaller skeletal dimensions (both longitudinal and transverse) and more subcutaneous fat than those with average or late menarche. The girls with late menarche have on average more height for weight than early maturers. Results indicate that there is a biological determinant of the observed association between menarcheal age and fatness and adult body size.     

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.     

Age at menarche and prevalence of oligo/amenorrhea in top Polish athletes

The representative sample of a population of top Polish athletes (>75% of all participants in Poland's Winter and Summer National Championships during 1992–1994) was investigated using a questionnaire. The athletic group numbered 926 women in total. The control group (n = 708) in the same age range (15–37 years) as the athletes was randomly chosen from the Warsaw population. The mean menarcheal age of all athletes was 13.6 ± 1.3 years, and it was statistically different from the controls (12.9 ± 1.2 years). Athletes who started training before menarche were more numerous (661) than those who started training after menarche (265). The mean menarcheal age was also different for those groups (13.9 ± 1.3 years vs. 13.0 ± 1.3 years). In all sports except cross-country skiing and biathlon, the menarcheal age of girls starting training before menarche was later as compared to the age of those starting training after menarche. The prevalence of oligo/amenorrhea (⩽9 menstrual cycles per year) was much higher for all younger and premenarche trained athletes than postmenarche trained girls. This prevalence also was much higher for athletes than for controls. Early maturers were engaged in team games, fencing, and judo, but late maturers were engaged in cross-country skiing and biathlon, track and field—long and middle distances, and marathon. It may indicate the presence of the sport's selection factor. Am. J. Hum. Biol. 10:511–517, 1998. © 1998 Wiley-Liss, Inc.     

Age at menarche and comparison of the growth and performance of pre- and post-menarcheal girls in China

The median menarcheal ages (MMAs) of Chinese girls in 1991 were calculated by using the status quo method and probit analysis in 64,322 schoolgirls 8–18 years of age. The sample was randomly selected from 29 provinces of China. The MMAs were 13.01 ± 1.19 and 13.64 ± 1.24 years for urban and rural girls, respectively. These estimates were 0.16 and 0.20 years lower than that of Chinese urban and rural girls in 1985, respectively. The associations between growth status and the timing of menarche were also analyzed by comparing of 10 indicators of somatic growth and motor ability between the pre- and post-menarcheal girls. Early maturers consistently have high means of stature, weight, and vital capacity than late maturers. By contrast, the late maturers tend to have a linear physique and more potential of increasing stature and lower limbs into late adolescence. Late maturers also tend to have more potential in catching up in motor abilities, which were inferior to those of early maturers during early adolescence. Am. J. Hum. Biol. 9:205–212, 1997. © 1997 Wiley-Liss, Inc.     

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.     

A comparative analysis of estimation of age at menarche by various methods in women participating in the Krakow Longitudinal Growth Study, Poland.

The purpose of this study was to see whether menarcheal age assessment by means of the most frequently used methods that were conducted every time on the same group of girls would yield the same results. One hundred and one Polish girls, whose ages at menarche were recorded in a longitudinal study between 1976 and 1990, were asked to recall the age of menarche in 2004. The mean menarcheal ages of those women were calculated by means of the probit (PA), prospective (AA), retrospective method without age correction (RA), and retrospective method with the recall age corrected by 0.5 year (RcA). The PA, AA, and retrospective methods: RA and RcA revealed results: 13.14 +/- 1.1; 13.10 +/- 1.1; 13.12 +/- 1.36, and 14.39 +/- 1.34 years, respectively. The menarcheal AA was insignificantly different from the PA (95% CI) and RA. The RcA was significantly higher than the AA and RA (P = 0.05). The correlation coefficient (r) between AA and RA was 0.70. Only 16% of the interviewed women accurately remembered the date of their menarche, 63% of them missed their menarche time by about 1 year, whereas 22% were wrong by 2 and more years. (1) The PA and the AA method yield comparable results when estimating menarcheal age. (2) The menarcheal age determined by the retrospective methods is not very reliable and the application of age correction overestimates the results.     

Deceleration of age at menarche in Poland.

The purpose of this paper is to describe secular growth changes in age at menarche of girls in Poland during the past 40 years. For this purpose data obtained from four consecutive surveys conducted in 1955, 1966, 1978 and 1988 were analysed. Each cohort was selected from settlements: big cities, small towns (approximately 10,000 inhabitants) and villages. Data regarding schoolgirls aged 7-18 years were collected by the status quo method. It was found that after the continuous trend towards an earlier maturation of Polish girls from 1955 to 1978 a substantial slowing down, and even a reverse trend, was observed. The deceleration of the age at menarche is most marked among girls from small towns. The results seem to have been caused by the retardation of menarcheal age in social groups which in the previous examinations were the earliest maturers.     

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.     

Adiposity and age of menarche in Hispanic women

Women with increased adiposity have been shown to have earlier menarche. However, the association between menarche and body fat distribution has been controversial. The present study examined relationships between several anthropometric data and age at menarche in 2,494 women aged 25 to 74 years from the Hispanic Health and Nutrition Examination Survey. Early menarche was similarly related to adiposity as measured by body mass index (BMI), skinfolds representative of central adiposity (subscapular and iliac), and skinfolds representative of peripheral adiposity (triceps and calf). These relationships persisted after controlling for a variety of influences such as socioeconomic status; they were consistent in all three ethnic groups studied, but were significant only in Puerto Rican women. Ratios of central/peripheral skinfold measures were not associated with menarche. These analyses describe the relationship between early maturation and overall adiposity in three distinct Hispanic groups and reject a specific association between menarche and central body fat distribution.     

Changes of recollected menarcheal age and month among women in Tokyo over a period of 90 years

Data on the recollected age at menarche of 47,881 women born between 1881 and 1970 were examined. The mean menarcheal age had changed from 15.1 years in those born up to 1900 to 12.5 years in those born during the 1960s. The age at menarche differed according to the month of birth, and the pattern of average age distribution by month of birth was not the same when the year of birth was different. Among women born before 1955 the menarcheal age was earlier in those born in the summer. However, among women born after 1955, menarche occurred later when they were born in the summer. The monthly distribution of menarche had also changed during this 90-year period. Two peaks in April and August were prominent among those born up to 1960. A third peak in January became also apparent in those born after 1960.     

Growth in stature in early,average, and late maturing children of the Caracas mixed-longitudinal study

A sample of 113 boys and 101 girls of the Caracas Mixed-Longitudinal Study was grouped into early, average, and late maturers according to selected cut-off points of the 10th and 90th centiles for age at peak height velocity (APHV). Individual curves were fitted with the cubic spline function, in which height velocity corresponds to the first derivative. Age at menarche (AM) was estimated by recall in a longitudinal context. Differences between groups were assessed with F and t-tests. Girls were approximately 2 years earlier than boys in APHV and thus significantly shorter; their estimated PHV was also significantly lower. APHV in boys and girls occurred 0.4–0.6 years earlier than in European children, which is consistent with a faster tempo of growth of Venezuelan youth. The three maturity groups differed significantly in timing, stature, and AM. Early maturers were taller than average maturers, and the latter were taller than late maturers with maximal differences between the extreme groups at ages 13–14 in boys and 11–12 in girls. Early maturers grew at a faster rate than average maturers, and the latter grew at a faster rate than late maturers up to 13 years in boys and 10–11 years in girls. Despite difficulties encountered in the analysis of mixed-linked longitudinal data, meaningful growth differences were found between maturity groups of urban Venezuelan children. © 1995 Wiley-Liss, Inc.     

The relation of adiposity and body size to chronological age in olive baboons

Mixed-longitudinal data on adiposity and body size were taken on 250 male and 452 female olive baboons aged between birth and 8 years. Adiposity was measured as skinfold thickness at the neck, subscapular, suprailiac, and triceps sites; body size measures included weight, crown-rump length, and triceps circumference. Males and females were treated independently and compared for gender differences. Data were tabulated to examine the relation of the somatometric variables to age and the patterns of association among the variables. Females averaged larger skinfold values at all sites for most ages. Males were significantly heavier, longer, and exhibited greater triceps girth at all ages except birth and 1 year where no significant gender difference was found for crown-rump length. In general the three measures of body size were significantly correlated at all ages as were the four measures of adiposity. Significant associations between adiposity and body size measures were not consistent among various ages.     

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 relation to anthropometric characteristics,competition level and boat category in elite junior rowers

BACKGROUND: Within the context of the effects of training for sports on growth and maturation, there is very little menarcheal data for elite rowing athletes. Knowledge of the relationship of the maturational status with training level, different boat categories, and somatic features of the athletes will clarify the assumed impact of rowing training on the growth and maturational process of youngsters. AIM: The aim of this study was to determine the age at menarche in world top junior rowing athletes and to investigate its relationship with anthropometric characteristics, and competition level, rowing style and boat category. SUBJECTS AND METHODS: The sample consisted of 212 female junior rowers, with a mean chronological age of 17.6 +/- 0.8 years, all participants at the 1997 FISA World Junior Rowing Championships. Anthropometric dimensions, somatotype and body composition characteristics were measured, and age at menarche and training data were retrospectively obtained by questionnaires. RESULTS: Results revealed that the mean age at menarche of the total group of rowers was 12.8 +/- 1.2 years and did not differ from a non-athletic reference population. Rowers who started their rowing training before menarche (n = 78) showed a significant (p 相似文献   

Age at menarche in relation to anthropometric characteristics,competition level and boat category in elite junior rowers

Background : Within the context of the effects of training for sports on growth and maturation, there is very little menarcheal data for elite rowing athletes. Knowledge of the relationship of the maturational status with training level, different boat categories, and somatic features of the athletes will clarify the assumed impact of rowing training on the growth and maturational process of youngsters. Aim : The aim of this study was to determine the age at menarche in world top junior rowing athletes and to investigate its relationship with anthropometric characteristics, and competition level, rowing style and boat category. Subjects and methods : The sample consisted of 212 female junior rowers, with a mean chronological age of 17.6 &#45 0.8 years, all participants at the 1997 FISA World Junior Rowing Championships. Anthropometric dimensions, somatotype and body composition characteristics were measured, and age at menarche and training data were retrospectively obtained by questionnaires. Results : Results revealed that the mean age at menarche of the total group of rowers was 12.8 &#45 1.2 years and did not differ from a non-athletic reference population. Rowers who started their rowing training before menarche ( n = 78) showed a significant ( p &#104 0.01) later age at menarche compared with rowers who started their training after menarche ( n = 134), with mean ages of 13.4 and 12.4 years, respectively. No significant relationship between the age at menarche and physical and body composition characteristics could be demonstrated, with r varying between &#109 0.11 and 0.11. Furthermore, no significant differences in ages at menarche between competition levels (finalists versus non-finalists/medallists versus non-medallists) and between the different boat categories could be observed. Conclusions : Based on the results of this study, there is no direct evidence to state that intensive rowing training has a negative influence on the maturation status of junior female athletes.     

Secular trend in the age at menarche in Haiti

Trends in age at menarche of 10,563 pregnant Haitian women enrolled in a longitudinal study of maternal mortality are examined. Mean recalled age at menarche for adult women in the sample was 15.37 years. However, there was a clear decline in mean menarcheal ages from the oldest to the youngest women, with a mean rate of decline for adult women of 0.36 years per decade. Mean menarcheal age was higher in each age group of rural women than for women in the metropolitan Port-au-Prince area; the rate of decline for adult rural women (0.37 years per decade) was nonsignificantly higher than that for adult metropolitan women (0.30 years per decade). The data suggest a secular decline in age at menarche in Haiti, as well as a continuing disparity between metropolitan and rural women. A declining age at menarche has important implications for fertility and reproductive health in Haiti, and may reflect a gradual improvement in health and nutritional status. © 1995 Wiley-Liss, Inc.