A continuous decline in menarcheal age in Denmark

We report a renewed decline in mean menarcheal age in a large Danish sample after a period with a halt in the trend towards earlier age at menarche in many North European countries. In our study based on retrospective data from six different samples constituting 42784 women, we find a continuously declining mean menarcheal age in Denmark among women born in the years 1964-1973. In a sample of textile workers born in the years 1939-1968 (n = 12605) we find a 1 year higher mean menarcheal age. This indicates that menarcheal age is still delayed in certain groups in Denmark. This leaves the possibility that the menarcheal age could fall even further in the future.     

Menarcheal age in Oslo during the last 140 years

Data from maternity clinics have been used to study the trend in menarcheal age among girls born in Oslo after 1840. The investigation was based on recordings from approximately 50 women from each year. The women were divided into social categories according to their own or their husband's occupation. The results show a trend toward earlier maturation within the working class, which is characterized by two periods of rapid fall in menarcheal age. The first period covers women born between 1860 and 1880, and shows a fall in menarcheal age from about 15·6 to about 14·6 years. During the second period of rapid fall, which covers women born between 1905 and 1940, the menarcheal age was further reduced from about 14·6 to 13·3 years. The age at menarche has been stable at about 13·3 years for women born after 1940.

These results contrast with those of some earlier studies of the menarcheal age in Norway. However, it is shown that the discrepancies between these investigations and our own disappear when the same computational methods and the same interpretation of the age recordings are used.     

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.     

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.     

Menarcheal age for Norwegian women born 1830-1960

Data from birth records from the maternity hospitals in the three main cities in Norway have been used to study the trend in menarcheal age for women born from about 1830 to about 1960. The investigation is based on a sample of 200-300 records around every 10th year from each of the three clinics in partly overlapping time periods relating to a total of 9152 women. The recollected age at menarche fell from just above 16 years for women born around 1830 to just above 13 years for those born around 1960, the decrease being not totally linear. These results correspond closely with a previously published investigation from Oslo from about the same period of time (Brudevoll, Liest?l and Wall?e, 1979), but our results, which cover more of Norway, show a more linearily shaped curve than the results covering only Oslo. We have also analysed the relationships of several independent variables to menarcheal age, using multivariate linear regression methods. Besides the woman's year of birth, which was the most important variable throughout the whole period of time, various geographical variables were found to be of moderate importance. Being born in the countryside and in towns other than Oslo and Bergen led to a slightly higher age at menarche. No significant difference between Oslo, Bergen and Trondheim was detected except for the period up to about 1880 where the Bergen women had about 2.6 months earlier menarche than the Oslo women. Married women amongst the sample had experienced menarche a little earlier than the unmarried, and among married women there was an association between occupation and menarcheal age, women from the lowest social classes having the latest ages at menarche. The importance of these socially related parameters declined with time, and for women born after 1945 the difference seemed to have disappeared. The age at menarche was found to be positively related to a woman's age at first birth; the further back in time the stronger the relation. In addition, delayed age at menarche was also found to be associated with irregularities in the menstrual cycles in later life.     

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.     

Menarcheal age for Norwegian women born 1830–1960

Data from birth records from the maternity hospitals in the three main cities in Norway have been used to study the trend in menarcheal age for women born from about 1830 to about 1960. The investigation is based on a sample of 200–300 records around every 10th year from each of the three clinics in partly overlapping time periods relating to a total of 9152 women. The recollected age at menarche fell from just above 16 years for women born around 1830 to just above 13 years for those born around 1960, the decrease being not totally linear. These results correspond closely with a previously published investigation from Oslo from about the same period of time (Brudevoll, Liestøl and Walløe, 1979), but our results, which cover more of Norway, show a more linearily shaped curve than the results covering only Oslo. We have also analysed the relationships of several independent variables to menarcheal age, using multivariate linear regression methods. Besides the woman's year of birth, which was the most important variable throughout the whole period of time, various geographical variables were found to be of moderate importance. Being born in the countryside and in towns other than Oslo and Bergen led to a slightly higher age at menarche. No significant difference between Oslo, Bergen and Trondheim was detected except for the period up to about 1880 where the Bergen women had about 2·6 months earlier menarche than the Oslo women. Married women amongst the sample had experienced menarche a little earlier than the unmarried, and among married women there was an association between occupation and menarcheal age, women from the lowest social classes having the latest ages at menarche. The importance of these socially related parameters declined with time, and for women born after 1945 the difference seemed to have disappeared. The age at menarche was found to be positively related to a woman's age at first birth; the further back in time the stronger the relation. In addition, delayed age at menarche was also found to be associated with irregularities in the menstrual cycles in later life.     

Age at menarche in a Chuvashian rural population

OBJECTIVES: The secular trend and familial influences on age at menarche among a rural Chuvashian population was examined in a cross-sectional community-based study. SUBJECTS AND METHODS: The cohort included 617 females aged 18-80 years, with age at menarche ranging from 10 to 24 years (mean 15.4 +/- 2.1). Statistical analyses included simple linear regression, maximum likelihood estimation and a whiskers plot. RESULTS: Women born during the second through the fourth decade of the 20th century showed increasing mean values of age at menarche from 15.4 (second decade) up to 16.5 (fourth decade). Women born after the fourth decade showed a decrease in mean values from 15.5 (fifth decade) to 13.0 (ninth decade). The highest peak of age at menarche was in women born in 1932. Significant familial correlations were observed between adjusted to year of birth age at menarche in mothers and daughters r = 0.195, p<0.01 and sisters and sisters r = 0.404, p<0.01. CONCLUSION: Our study demonstrated the certain secular trends of age at menarche in Chuvashian women who matured after World War II. Periods of socio-economic disasters such as war and famine disrupt the secular trend. Our findings also confirm the hypothesis of significant familial influences on menarcheal age.     

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.     

Social background and age at menarche in Portuguese university students: A note on the secular changes in Portugal

Menarcheal age of a sample of Portuguese university students (n = 3,366), born between 1972 and 1983, age 18–23 years, was analyzed. The influence of parents' educational level and occupation, family size, birth order, and degree of urbanization of girl's locality of residence during childhood and adolescence were analyzed as well as secular trend in the Portuguese population. Mean age at menarche for girls born in 1983 was 12.32 years. Parents' educational level and occupation did not show any significant influence on mean age at menarche. Place of residence during childhood years and adolescence showed a significant effect on mean age at menarche, with girls from rural places with a later age at menarche than those who spent their childhood or adolescence in urban areas (P ≤ 0.01 and P ≤ 0.05 for childhood and adolescence, respectively). Family size and birth order showed the highest effect. Girls born in small families, with one child, matured earlier (12.32 years) than those born in large families with four or more children (12.67 years), (P ≤ 0.01). Also, girls that were first‐born had an earlier menarche (12.41 years) than those who were third or later (12.58 years, P ≤ 0.01). Regression analysis selected family size and place of residence in childhood as the most important determinants of mean age at menarche in our university students. In this sample, from 1972 to 1983, mean age at menarche remained stable. When we considered published data from all the Portuguese population we found a decrease in mean age at menarche from 15 years for girls born in 1880 to 12.44 for those born in the 1980s. This decrease was the result of great improvements in the social and economic living conditions that occurred in Portugal especially after the 1970s concerning nutrition and health care, among many other environmental factors. Am. J. Hum. Biol. 15:415–427, 2003. ©2003 Wiley‐Liss, Inc.     

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.     

Distance of walking in childhood and femoral bone density in perimenopausal women

Kuopio osteoporosis risk factor and prevention (OSTPRE) study is a population-based study from Eastern Finland. At baseline in 1989–91, bone densitometry of lumbar spine and femoral neck as assessed by DXA was carried out on women aged 48–58 (n = 3,222). In 1993, menarcheal age and health habits during adolescence were inquired from a postal inquiry. In 1996, a random sample of 254 women who had been premenopausal at baseline was interviewed over phone. They were asked how many kilometers per day they had walked to school and back, in each grade of primary school. The study sample (N = 185) was formed by excluding women with menarcheal age of >14 or <11 years. Women with any reported HRT history were also excluded. The mean age of the study sample was 50.7 (1.63) years, weight 70.8 (13.1) kg, height 161.5 (5.0) cm, and mean walking distance to and fro from the school at ages from 9 to 11 years was 2.7 (1.7) km. In regression analysis, the walking distance was associated with femoral BMD (r = 0.18, P = 0.015). After adjusting for baseline age, weight and height, this association persisted (P = 0.025). When walking distance was categorized as I = 0–0.549 km, II = 0.55–1.99 km, III = 2.0–4.99 and IV = 5.0 km and more, the respective means for femoral BMDs were 0.92, 0.97, 0.98 and 1.01 g/cm². Statistical significance persisted after adjusting for height, weight, age, grip strength, calcium intake, smoking, place of residence, use of contraceptive pills, physical load of work and baseline physical activity (P = 0.032). A 10 year follow-up revealed no changes in bone loss rate between the groups and femoral BMD benefits persisted (repeated measures analysis = NS). Walking distance was not associated with spinal bone density. Even though walking is a low impact activity, walking before menarche may have a moderate but long-lasting positive effect on femoral peak bone density. Lack of walking and similar low impact physical activities during peak growth years may have a negative effect on peak bone mass formation.     

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.     

Secular trends in growth and maturation in British girls

Over a period of 28 years, a succession of cross-sectional surveys was carried out on young women entering the University College of Swansea (1959–1970) and then the University of Warwick (1971–1986) each year. Recall data on age at menarche and measurements of stature provide an indication of secular trends in growth and maturation in this section of the population of Britain. The earlier trend to younger age at menarche came to an end in girls born in approximately 1946 and entering university in 1964, and subsequently reversed, so that there is now a secular increase in menarcheal age. The successive analyses of stature show no such reversal, but instead a steady increase in mean stature throughout the period. © 1994 Wiley-Liss, Inc.     

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.     

Time-related trends of age at menopause and reproductive period of women in a Chuvashian rural population

OBJECTIVE: The objective of this study was to examine in an observational, cross-sectional, community-based study the secular trend of age at menopause among women in a rural Chuvashian population and to identify factors associated with age at menopause. DESIGN: The sample included 316 postmenopausal women born between 1920 and 1950 with mean age at menopause of 48.47 +/- 4.63 (34-58) years. Statistical analyses included simple and multiple linear regression and "whiskers" plots. RESULTS: Significant association was found between year of birth and age at menopause (beta = 0.194, P < 0.001) and reproduction period (P = 0.193, P < 0.001). Mean values of age at menopause increased from 47.0 years (born during 1920-1925) to maximal values of 49.7 years (born during 1940-1945) and 49.3 years (born during 1945-1950). Mean values of their reproductive period increased from 30.7 (born during 1920-1925) to maximal values of 34.1 (born during 1940-1945) and to 33.7 (born during 1945-1950). Multiple linear regression analysis demonstrated that year of birth was the only statistically significant (P = 0.19, P < 0.01) predictor of age at menopause. Age at menarche can also be a possible predictor of age at menopause (beta = -0.12, P = 0.04). CONCLUSIONS: The study confirmed certain secular trends of age at menopause and reproductive periods in Chuvashian women. The authors also observed a negative association between age at menarche and age at menopause. The number of children and medical abortions as well as body mass index showed no association with age at menopause.     

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.     

Menarcheal age and habitual miscarriage: evidence for an association

Among women who habitually miscarried (two or more miscarriages) we observed a modest association for increased risk of miscarriage of first pregnancies in those with younger (especially less than or equal to 11 years) and older (greater than or equal to 16 years) menarcheal age (quadratic G2 = 3.49, P = 0.062). No associations of menarcheal age with first pregnancy miscarriage were observed when analysed by age at first pregnancy, or with pregnancy number among women with only one miscarriage. Unusually early or late menarcheal age appears to increase the risk of miscarriage of the first pregnancy but only among women who will go on to habitually miscarry.     

Secular trend in age at menarche for South Korean women born between 1920 and 1986: the Ansan Study

BACKGROUND: There is strong evidence of a downward secular trend in age at menarche in Europe and the USA during the last century and in Japan and China during the past few decades. However, no study on this trend in age at menarche has been reported in South Korea. AIM: To measure the trend in age at menarche in South Korea during the past few decades and the association of height with this trend. SUBJECTS AND METHODS: A total of 1061 South Korean women born between 1920 and 1986 were randomly recruited from Ansan Cohort Study samples and separate school girl samples, and subjected to this analysis. The data on age at menarche were collected by the retrospective method. Height was measured at time studied and assumed to be relatively constant since age at menarche. Women were grouped with respect to decade of birth and mean age at menarche was determined. The secular trends in annual age at menarche and in height were analysed by the 3-year moving average. RESULTS: Mean menarcheal age decreased from 16.8 to 12.7 years during the past 67 years, corresponding to -0.64 years per decade. Height increased from 149.23 to 161.75 cm during the same period, showing an inverse relationship in the change of trend between height and mean age at menarche. CONCLUSION: Our data suggest that the downward secular trend in age at menarche may reflect the secular change in physical growth in South Korean women during the past 67 years.