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This study seeks to further elucidate the mother–daughter hormonal relationship and its effects on daughter’s breast cancer risk through the association with early age at menarche. Four hundred and thirty-eight healthy girls, age 9–18 and of White, Asian, and/or Polynesian race/ethnicity, were recruited from an HMO on Oahu, Hawaii. Anthropometric measures were taken at a clinic visit, and family background questionnaires were completed. Cox proportional hazards regression was used to test the association of maternal and intrauterine hormone-related exposures with age at menarche. Weight and gestational age at birth and maternal pregnancy-induced nausea were not associated with age at menarche. Each year older of the mother’s age at menarche was associated with a 21% reduced risk of an early age at menarche for the daughter (95% CI: 0.73–0.86). This association between mother’s and daughter’s menarcheal age was statistically significant for girls of Asian, White, and Mixed, Asian/White race/ethnicity, but not for girls of Mixed, part-Polynesian race/ethnicity (pinteraction = 0.01). There was a suggestion that maternal history of breast cancer was associated with an increased risk of early age at menarche (HR = 2.18, 95% CI: 0.95–4.98); there was no association with second-degree family history. These findings support the hypothesis that maternal and intrauterine hormone-related exposures are associated with age at menarche.

Ages at menarche and menopause have been shown to be associated with adverse health outcomes in later life. For example, earlier menarche and later menopause have been independently linked to higher risk of breast cancer. Earlier menarche may also be associated with an increased risk of endometrial cancer, menstrual problems and adult obesity. Given the associations of ages at menarche and menopause with future health outcomes, it is important to establish what factors across life, and generations, may influence these. This article examines the associations of early life factors, namely birthweight, bodyweight and growth during childhood, childhood socioeconomic circumstances and psychosocial factors with ages at menarche and menopause. It examines possible explanations of the associations found, including life history theory, and discusses areas for future research.

Age at menarche, a sentinel index of pubertal maturation, was examined in relation to early family relationships (conflict, cohesion) and polymorphic variation in the gene encoding estrogen receptor-α (ESR1) in a midlife sample of 455 European American women. Consistent with prior literature, women who reported being raised in families characterized by close interpersonal relationships and little conflict tended to reach menarche at a later age than participants reared in families lacking cohesion and prone to discord. Moreover, this association was moderated by ESR1 variation, such that quality of the family environment covaried positively with menarcheal age among participants homozygous for minor alleles of the two ESR1 polymorphisms studied here (rs9304799, rs2234693), but not among women of other ESR1 genotypes. In addition, a) family relationship variables were unrelated to ESR1 variation, and b) genotype-dependent effects of childhood environment on age at menarche could not be accounted for by personality traits elsewhere shown to explain heritable variation in reported family conflict and cohesion. These findings are consistent with theories of differential susceptibility to environmental influence, as well as the more specific hypothesis (by Belsky) that girls differ genetically in their sensitivity to rearing effects on pubertal maturation.

A multiethnic cohort of 1378 Southern California school girls aged 8–13 years was followed for 4 years to evaluate factors predicting age at menarche, a risk factor for breast cancer. Height and weight were measured and dietary intake was assessed using a semi-quantitative food frequency questionnaire. Of 939 girls providing data on menarcheal status, 767 were premenarcheal at the start of the study; 679 girls provided acceptable dietary data and were included in the analyses. Cox proportional hazards models were used to assess the relationship between diet, body size, ethnicity and age at menarche. Hispanic, Asian/Pacific Island and African-American girls were more likely to experience early menarche than non-Hispanic white girls. Tall (> 148.6 cm) versus short (< 135.9 cm) girls experienced earlier menarche (relative hazard (RH) = 2.9, 95% confidence interval (CI) 2.1–4.1) as did those with high Quetelet's index (QI, kg m−2) (> 20.7) versus low QI (< 16.1) (RH = 2.2, 95% CI 1.7–2.9). Of all the dietary variables analysed, only energy intake was related to age at menarche. High versus low energy intake (> 12013 kJ vs < 7004 kJ) was associated with a delay in menarche (RH = 0.7, 95% CI 0.5–0.9); this finding was limited to a subset of heavy Hispanic girls who appeared to underreport their dietary intake. © 1999 Cancer Research Campaign

Background

Puberty is a transition period making physiological development a challenge adolescents have to face. Early pubertal development could be associated with higher risks of poor health. Our objective was to examine risk behaviours, physical and psychological determinants associated with early menarche (<11 years).

Methods

Early menarche was assessed in the Health Behaviour in School-aged Children French cross-sectional survey. Data were collected in 2006 by anonymous self-reported standardized questionnaire from a nationally representative sample of 1072 15 years old girls in school classrooms. Family environment, school experience, physical and psychological factors, risk behaviours (substance use and sexual initiation) were recorded. Logistic regression models were applied (analysing for crude and adjusted relationships between early menarche and risk behaviours controlled for family context).

Results

Median age at menarche was 13.0 years; 57 girls (5.3%) were early-matured. Controlled for familial environment, early menarche was associated with having had more than two life-drunkenness episodes (adjusted OR = 2.5 [1.3-4.6]), early sexual initiation (adjusted OR = 2.8 [1.3-6.0]) and overweight (adjusted OR = 7.3 [3.6-14.9]).

Conclusion

Early-maturing girls may affiliate with older adolescents, hence engage in risk behaviours linked to their appearance rather than their maturity level. Factors associated with early menarche highlight the need to focus attention on early-matured girls to prevent further health problems linked to risk behaviours.

Diethylstilbestrol (DES), a synthetic estrogen used in pregnancy during the 1950s and 1960s, provides a model for potential health effects of endocrine disrupting compounds in the environment. We evaluated prenatal exposure to DES, based on medical record review, in relation to gestational length, fetal growth, and age at menarche in 4429 exposed and 1427 unexposed daughters. DES exposure was associated with an increase in preterm birth (odds ratio (OR) = 2.97; 95%CI=2.27, 3.87), and a higher risk of small for gestational age (SGA) (OR=1.61; 95% CI=1.31,1.98). The association between DES exposure and early menarche was borderline, with stronger effects when early menarche was defined as <= 10 years (OR = 1.41 95%CI=0.97, 2.03) than defined as <= 11 years (OR=1.16; 95%CI=0.97, 1.39). This study provides evidence that prenatal DES exposure was associated with fetal growth and gestational length, which may mediate associations between DES and health outcomes in later life.

Background

Age at menarche is the reflection of cumulative pre-adolescent exposure of girls to either adverse environment such as food insecurity or affluent living conditions. Food insecurity could result in inadequate nutrient intake and stress, both of which are hypothesized to have opposing effects on the timing of menarche through divergent pathways. It is not known whether food insecure girls have delayed menarche or early menarche compared with their food secure peers. In this study we test the competing hypothesis of the relationship between food insecurity and age at menarche among adolescent girls in the Southwest Ethiopia.

Methods

We report on 900 girls who were investigated in the first two rounds of the five year longitudinal survey. The semi-parametric frailty model was fitted to determine the effect of adolescent food insecurity on time to menarche after adjusting for socio-demographic and economic variables.

Results

Food insecure girls have menarche one year later than their food secure peer (median age of 15 years vs 14 years). The hazard of menarche showed a significant decline (P = 0.019) as severity of food insecurity level increased, the hazard ratio (HR) for mild food insecurity and moderate/severe food insecurity were 0.936 and 0.496, respectively compared to food secure girls. Stunted girls had menarche nearly one year later than their non-stunted peers (HR = 0.551, P < 0.001).

Conclusion

Food insecurity is associated with delay of age at menarche by one year among girls in the study area. Stunted girls had menarche one year later than their non-stunted peers. Age at menarche reflects the development of girls including the timing of sexual maturation, nutritional status and trajectory of growth during the pre-pubertal periods. The findings reflect the consequence of chronic food insecurity on the development and well-being of girls in the study area.

Girls who grow up in households with an unrelated adult male reach menarche earlier than peers, a finding hypothesized to be an evolutionary strategy for families under stress. The authors tested the alternative hypothesis that nonrandom selection into stepfathering due to shared environmental and/or genetic predispositions creates a spurious relation between stepfathering and early menarche. Using the unique controls for genetic and shared environmental experiences offered by the children-of-twins design, the authors found that cousins discordant for stepfathering did not differ in age of menarche. Moreover, controlling for mother’s age of menarche eliminated differences in menarcheal age associated with stepfathering in unrelated girls. These findings strongly suggest selection, and not causation, accounts for the relationship between stepfathering and early menarche.

Using an ‘at-risk’ sample of African American girls, the present study examined the link between girls' retrospective reports of pubertal timing, girls' perceived relative pubertal timing, and their behavioral and emotional problems as rated by the girls themselves (N = 102; 11 to 17 years), as well as teachers and parents. Structural equation modeling results indicated that the girls' retrospective reports of menarche were significantly related to their perceived relative menarche, whereas the girls' retrospective reports of development of their breasts were not related to their perceived relative development of breasts. Girls who perceived their breasts developing early relative to their peers were more likely to engage in delinquent behaviors according to teacher report. Significant effects of teacher reported adolescent internalizing problems also were found for girls who retrospectively reported either early or late development of breasts. The study's findings underscore the importance of teasing apart the effects of different indicators of girls' pubertal development on psychosocial adjustment and including teachers' reports of girls' emotional and behavioral problems, particularly among girls with the additional risks associated with residing in an economically disadvantaged urban setting.

Background

Early menarche is related to increased risk of breast cancer. The number of established factors that contribute to early menarche is limited. We studied prenatal and infant exposures in relation to age at menarche in a nationwide cohort of women who have a family history of breast cancer.

Methods

The study comprised 33,501 women in the Sister Study who were aged 35-59 years at baseline (2003-2009). We used polytomous logistic regression to estimate separate relative risk ratios (rRRs) and 95% confidence intervals (CIs) for associations of self-reported exposures with menarche at ≤10, 11, 14, and ≥15 years relative to menarche at 12-13 years.

Results

Early menarche (≤10 or 11 years) was associated with having low birth weight, having had a teenage mother, being firstborn, and specific maternal prenatal exposures: smoking, DES (diethylstilbestrol), pre-pregnancy diabetes, and pregnancy-related hypertensive disorder. Prenatal exposures most strongly associated with very early menarche (≤10 years) were DES (rRR = 1.56 [95% CI = 1.24-1.96]), maternal pre-pregnancy diabetes (2.24 [1.37-3.68]), and pregnancy-related hypertensive disorder (1.45 [1.18-1.79]). Soy formula was associated with both very early menarche (1.21 [0.94-1.54]) and late menarche (14 years: 1.17 [0.98-1.40] or ≥15 years: 1.28 [1.06-1.56]).

Conclusions

Although menarche is only one marker of pubertal development, it is a commonly used surrogate. The observed associations of prenatal DES and soy formula exposure with age at menarche are consistent with animal data on exogenous estrogens and pubertal timing. Early-life exposures may confound associations between age at menarche and hormonally dependent outcomes in adults.

Height and weight at menarche were estimated by interpolation of longitudinal growth data for 181 girls. Mean weight at menarche, about 48 kg, does not change as menarcheal age increases, whereas mean height increases significantly. Early and late menarcheal girls gain the same amount of height, about 22 cm, and the same amount of weight, about 17 kg, in the interval from the initiation of the adolescent spurt to menarche, though late maturers grow at slower rates during the spurt, including the year of menarche. A hypothesis of a direct relation between a critical weight and menarche is proposed. Such an interaction would explain the delaying effect of malnutrition on menarche and the secular trend to an earlier menarche.

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.

Menarche is a discrete, transitional event that holds considerable personal, social, biological, and developmental significance. The present longitudinal study examined both the transition and timing of menarche on the trajectory of anxiety in girls with histories of childhood maltreatment (N = 93; 63% European American, 14% multiracial, 10% Latino, 9% African American, and 4% Native American). We hypothesized that because menarche is a novel, unfamiliar experience, girls would show greater anxiety around the time of menarche. The anxiety-provoking nature of menarche may be accentuated among earlier-maturing girls and girls with histories of childhood sexual abuse. Results indicated that earlier-maturing girls were more anxious in the pre- and peri-menarche periods than their later-maturing peers; however, their anxiety declined after menarche. Childhood sexual abuse was associated with heightened anxiety throughout this transition. The developmental significance of the timing and transition of menarche in relation to childhood sexual abuse and anxiety is discussed.

Purpose

We evaluated the association between childhood socioeconomic status (SES) at two time points and age at menarche in a multiracial sample of U.S. girls.

Methods

Our study population consisted of a cohort of female participants enrolled at birth in the New York site of the Collaborative Perinatal Project, born 1959–1963 (n=262). SES at birth, at age 7, and change between birth and age 7 were measured prospectively through an index score of family income, paternal occupation, and education. Data on age at menarche were collected retrospectively through adult self-report. We used multivariable linear regression to examine the association between SES and age at menarche after adjusting for childhood body mass index (BMI) and other covariates associated with age at menarche.

Results

After adjustment, SES at age 7 was positively associated with age at menarche (beta: 0.015, CI: 0.003, 0.024 per unit of SES index). Change in SES was significantly associated with age at menarche; a 20 unit decrease in SES was associated with a 4 month decrease in age at menarche.

Conclusions

Our results suggest that lower SES at 7 years and reductions in SES in early childhood are both associated with an earlier age at menarche.

The study aims to assess the relation between breastfeeding duration and age at menarche. Analysis was based on a cohort of 994 Filipino girls born in 1983–1984 and followed up from infancy to adulthood by the Cebu Longitudinal Health and Nutrition Survey. The main outcome was self-reported age at menarche. Cox regression was used to investigate the relation between duration of exclusive and any breastfeeding with age at menarche with adjustment sequentially for specific sets of known socioeconomic, maternal, genetic, and prenatal confounders. The estimated median of age at menarche was 13.08 years. After adjustment for potential confounders of the association of breastfeeding with age at menarche, exclusive breastfeeding duration retained an independent and significant association with age at menarche. An increase in 1 month of exclusive breastfeeding decreases the hazard of attaining earlier menarche by 6% (hazard ratio = 0.94, 95% confidence interval: 0.90, 0.98). Any breastfeeding duration was not associated with age at menarche. Although this is the first longitudinal study that reveals a negative association between exclusive breastfeeding and early menarche, the relation is still elusive. Further longitudinal studies within different contexts are warranted to assess the generalizability of these findings.

In the National Child Development Study (1958 cohort) information on their age at menarche and their weights and heights measured at 7, 11, and 16 years was available for 4427 girls. The distribution of age at menarche was not influenced by social class. Weight adjusted for height did not play an important part in the timing of sexual maturation of the girls in the study. Relative weight (weight expressed as a percentage of standard weight) at the ages of 7 and 11 years explained only 3.2%, and 4.9%, respectively of the variation in age at menarche, and changes in relative weight between these two ages accounted for 2%. Girls with early menarche were more likely to be overweight at ages 7, 11, and 16 years than those with late menarche, although early menarche was also reported by girls who were underweight or of average weight. These findings support the hypothesis that in well nourished populations the relation between menarche and body size is largely regulated by genetic factors and that nutrition is less important.

Purpose

Westernized eating habits have been associated with early-age menstruation, which increases the incidence of dysmenorrhea and premenstrual syndrome among adolescent girls. We therefore surveyed changes in menarche timing and the general menstrual characteristics of adolescent girls in Seoul, Korea.

Methods

We surveyed 538 teenage girls who visited our hospital between July and November 2007. Items explored included age at menarche, general menstrual characteristics, occurrence of premenstrual syndrome and treatment thereof, and an association between present dysmenorrhea and a family history of the condition.

Results

Average age at menarche was 12.6 years, with 29% (n=156) subjects beginning menstruation at age 12 years. The prevalence of dysmenorrhea was 82% (n=435). The main symptoms were abdominal (53.2%) and lower back pain (34.2%), and 15.2% of girls who experienced such symptoms required medication. Present dysmenorrhea, and a family history thereof, were statistically correlated (P<0.05). In addition, 58.8% (n=316) of teenage girls had symptoms of premenstrual syndrome. The most frequent psychological symptoms were fatigue (36.4%) and nervousness (38.7%), whereas the most common physical symptom was menstrual cramps (46.5%). Most subjects (87.6%) tolerated the symptoms of premenstrual syndrome without medication; 11.4% took medicines including painkillers; but only 0.1% of subjects visited a doctor.

Conclusion

The average age at menarche in Korean girls was 12.6 years, thus younger than in the past. Most teenage girls experienced dysmenorrhea and premenstrual syndrome, but few consulted a doctor. Organized treatment plans are required to manage menstrual problems in teenage girls.

Context

Precocious onset of menses (ie, age ≤11 years) has repeatedly been identified as a risk factor for higher rates of delinquency or conduct disorder (CD) in girls. Although this association is often conceptualized as environmentally mediated (via processes such as affiliation of early-menstruating youth with older, more deviant peers), such conclusions are premature as biological and genetic explanations have yet to be fully considered.

Objective

To uncover the origins of the association between CD and timing of menarche.

Design, Setting, and Participants

The sample consisted of a population-based birth cohort of 708 mid-adolescent female twins assessed as part of the ongoing Minnesota Twin Family Study. We conducted 2 sets of analyses: standard bivariate analyses to uncover possible common genes and moderator analyses to evaluate possible moderation of genetic influences on CD by timing of menarche.

Main Outcome Measures

Conduct disorder was assessed via individual semistructured interviews with mothers and adolescents. Menarcheal status and age at menarche were assessed via the Pubertal Development Scale.

Results

The results argued against common genetic influences but did provide evidence of etiological moderation of CD by timing of menarche. The heritability of CD was strongest (67%) in girls with average timing of menarche (ie, age 12–13 years) and substantially weaker (8%) in those with early onset. Those with late initiation of menses (ie, age >13 years) similarly exhibited weaker genetic influences (29%). Shared environmental influences showed the opposite pattern, as they were far stronger for those with precocious and delayed onset vs those with average onset.

Conclusions

Our findings provide indirect support for psychosocial interpretations of the impact of precocious menarche and, to a lesser extent, delayed menarche on CD development. Further, they lend support to the notion that in some cases, genetic influences on psychopathology may be strongest in the “average, expectable” environment.

Background

Early life-stage exposure to estrogen increases the risk of breast cancer. The objective of this study was to investigate the age at menarche and time to onset of regular menstrual cycles for Japanese women born between 1930 and 1985.

Methods

A cross-sectional study was designed using data from the baseline survey of the Japan Nurses’ Health Study. The data from 48,104 female nurses were analyzed. To view trends in age at menarche, the distribution of age at menarche was calculated for each birth year cohort. The distribution of time to onset of regular menstrual cycles was calculated for each birth year cohort. To estimate whether high-risk group of the estrogenic dependent disorders increase with succeeding generations, we defined the women who experienced menarche at ten years old or younger and started a regular cycle within one year as early age onset of ovulatory cycles.

Results

Average ages at menarche were as follows: 13.8 years for those born in the 1930s (n = 113), 13.3 years for the 1940s (n = 4,751), 12.8 years for the 1950s (n = 15,844), 12.3 years for the 1960s (n = 20,547), 12.2 years for the 1970s (n = 6,568), and 12.2 years for the 1980s (n = 281). The proportion of women who experienced the onset of regular menstrual cycles 1 year after menarche was 29.3% for those born in the 1930s, but decreased to 11.9% for the 1980s. On the other hand, the proportion of women who did not have regular menstrual cycles was 10.4% for those born in the 1930s, but rose to 19.8% in 1980s. The proportion of women who experienced menarche at 10 years old and started regular menstrual cycles within one year increased over time: the percentage was 0.0%, 0.4%, 0.6%, 1.1%, 1.3%, and 2.1% for the women born in 1930s, 1940s, 1950s, 1960s, 1970s, and 1980s, respectively.

Conclusions

The age at menarche of Japanese women born between 1930 and 1985 decreased, but the onset of regular menstrual cycling is delayed; so that the distribution of the start time of ovulatory cycles may have spread for younger generations. Those suggest that the high-risk group of estrogenic dependent diseases among Japanese women may increase in the near future.

SUMMARY

This study examines the timing of menarche in relation to infant feeding methods, specifically addressing the potential effects of soy isoflavone exposure through soy-based infant feeding. Subjects were participants in the Avon Longitudinal Study of Parents and Children (ALSPAC). Mothers were enrolled during pregnancy and their children have been followed prospectively. Early life feeding regimes, categorized as primarily breast, early formula, early soy, and late soy were defined using infant feeding questionnaires administered during infancy. For this analysis, age at menarche was assessed through questionnaires administered approximately annually between ages 8 and 14.5. Eligible subjects were limited to term, singleton, white females. We used Kaplan-Meier survival curves and Cox proportional hazards models to assess age at menarche and risk of menarche over the study period.

The present analysis included 2,920 girls. Approximately 2% of mothers reported that soy products were introduced into the infant diet at or before 4 months of age (early soy). The median age at menarche [interquartile range (IQR)] in the study sample was 153 months [144–163], approximately 12.8 years. The median age at menarche among early soy fed girls was 149 months (12.4 years) [IQR, 140–159]. Compared to girls fed non-soy based infant formula or milk (early formula), early soy fed girls were at 25% higher risk of menarche throughout the course of follow up (Hazard Ratio 1.25 [95% confidence interval, 0.92, 1.71]). Our results also suggest that girls fed soy products in early infancy may have an increased risk of menarche specifically in early adolescence. These findings may be the observable manifestation of mild endocrine disrupting effects of soy isoflavone exposure. However, our study is limited by few soy-exposed subjects and is not designed to assess biological mechanisms. Because soy formula use is common in some populations, this subtle association with menarche warrants more indepth evaluation in future studies.

Age at menarche is closely related to scoliosis progression during adolescence. Current data concerning the timing of menarche between scoliotic and non-scoliotic girls in the literature are conflicting, with inconclusive results. The aim of this study was to investigate the distribution difference of age at menarche for adolescent idiopathic scoliosis (AIS) girls and normal control population and to subsequently elucidate the menarche age difference through literature reviewing. Moreover, menarche age of AIS girls with Cobb angle <40°, 40–60°, >60° were compared to estimate its association with curve severity. Menstrual status data were available for 6,376 healthy female adolescents and 2,196 AIS girls. We notice that less than 10% of healthy Chinese girls experienced onset of menses before 11.38 years, and approximately 90% of healthy Chinese girls were menstruating by 13.88 years, with a median age of 12.63 years. As for AIS girls, less than 10% started to menstruate before 11.27 years, and approximately 90% were menstruating by 14.38 years, with a median age of 12.83 years. Average menarche age in AIS (12.83 ± 1.22 years) was significantly later than that of normal control girls (12.63 ± 0.98 years) (p < 0.001). Age at menarche for AIS affected girls was significantly greater than that of normal control girls at 75%, 90% of whom had attained menarche (p = 0.001, p < 0.001). Proportion of girls starting to menstruate after 14 years was significantly higher in AIS population compared with normal controls (16.3 vs. 8.1%, p < 0.001). In addition, AIS girls with Cobb angle >60° experienced onset of menses at an average age of 13.25 years, which was significantly later than AIS girls with Cobb angle <40° (12.81 years, p < 0.05) and marginally significantly later than AIS girls with Cobb angle between 40 and 60° (12.86 years, p = 0.053). In conclusion, a tendency of delayed onset of menarche was observed in Chinese idiopathic scoliotic girls in this large sample study, especially for girls with Cobb angle >60°, which is supported by multiple previously established positive linkages on AIS etiology studies. Accordingly it is believed that late menarche may contribute importantly to abnormal pubertal growth and subsequently modulate curve behavior in AIS.

Objectives

We examined the association between childhood abuse and early menarche in a sample of US Black women.

Methods

We conducted multivariable log-binomial regression on data from 35330 participants in the Black Women’s Health Study to estimate risk ratios and 95% confidence intervals for the relation of childhood physical and sexual abuse with early age at menarche (i.e., <12 years).

Results

In adjusted analyses, sexual abuse was positively associated with early menarche, and the risk of early menarche increased with increasing frequency of sexual abuse incidents. We observed a weak but statistically significant association between physical abuse and early menarche. Associations between sexual abuse and early menarche were stronger when we used a more stringent cutpoint for early menarche (i.e., <11 years).

Conclusions

Our data suggest an increased risk of early menarche among Black women who experienced childhood sexual abuse. Evidence for an association between childhood physical abuse and early menarche was equivocal.

Background

Because of the rapid increases in childhood obesity coupled with decreases in the median age of menarche, there is interest in how growth (body mass index [BMI] and height) in childhood may be associated with timing of menarche.

Objectives

Two research questions were addressed in this paper: (a) Within each race, at what ages were BMI and height differences evident among the early-, mid-, and late-onset groups? and (b) Within each timing group, at what ages were BMI and height differences evident between White and African American girls?

Methods

The Mother/Child files of the National Longitudinal Survey of Youth were used for this study. Menarcheal timing groups were identified using the 25th and 75th percentile of the age distribution for each race. Longitudinal statistical techniques were employed to estimate BMI and height as polynomial functions of age and age relative to menarche for African American and White girls.

Results

Significant differences in BMI by timing group were found. By age 3 years significant differences were found between early- and mid-onset African American girls, by age 5 years between mid- and late-onset African American girls, and by 6 years among the three timing groups of White girls. Significant height differences were evident by age 5 years when comparing early- to mid-onset and mid- to late-onset girls in both race groups. Comparing across race and within timing group, BMI and height differences were evident. African American girls were more likely than White girls to experience accelerated growth and earlier menarche.

Discussion

This is one of the few longitudinal studies of differences in growth by timing of menarche that includes data on girls younger than 5 years with large samples of both African American and White girls. Understanding when differences are first apparent is critical in establishing the critical period for prevention of these high-risk growth patterns.

Background:

The menstrual practices of adolescents derive largely from health issues associated with their adjustment to reproductive life. The objective of the study was to assess the effect of pre-menarcheal training on the menstrual and hygiene practices of Nigerian school girls.

Method:

A cross-sectional questionnaire-based survey of randomly selected post-menarcheal school girls using a pre-tested, semi-structured questionnaire was done.

Results:

The mean age of the school girls was 14.9 ± 1.7 years. Pre-menarcheal training was given to 273 (55.2%) of them. Mothers (74.7%) were the more common source of information. Inappropriate experience of menarche, adverse effect of menstruation on schooling and social life and the use of unhygienic menstrual absorbents were common in girls who had no pre-menarcheal training than those who did.

Conclusion:

Lack of timely information results in inappropriate menstrual experiences and poor menstrual hygiene practices. Ways to promote menstrual education and hygiene practices are suggested.

Taking a life course approach to the study of reproductive health involves the investigation of factors across life and, also across generations, that influence the timing of menarche, fertility, pregnancy outcomes, gynaecological disorders, and age at menopause. It also recognises the important influence of reproductive health on chronic disease risk in later life. Published literature supports the use of an integrated life course approach to study reproductive health, which examines the whole life course, considers the continuity of reproductive health and the interrelationship between the different markers of this. This is in contrast to more traditional approaches that tend to focus only on contemporary risk factors and which consider each marker of reproductive health separately. For instance, we found evidence linking early life factors such as growth, socioeconomic conditions, and parental divorce with ages at menarche and menopause, although the nature of the relationship differs. We discuss the different theoretical models that are used within life course epidemiology and which postulate pathways linking exposures across the life course to health outcomes, using examples of relevance to the study of reproductive health. These highlight the importance of examining timing of exposures, such as during critical periods in early life, and the temporal order of exposures. How life course frameworks of reproductive health can be developed to help identify hypotheses to be tested is also demonstrated. This approach has implications for the development of effective health policy that moves beyond identifying not only the type of intervention but also the most appropriate time across life to intervene.