Age at menarche in contemporary Greek girls: evidence for levelling-off of the secular trend

Indications of younger age at menarche in Greek adolescents but with no relation to body mass index

PURPOSE

This study aimed to present recent trends in the pubertal timing of a Greek female sample.

METHODS

Data were collected retrospectively from medical records of healthy females aged 6-18 years who attended a tertiary Adolescent Friendly Health Center over a 5-year period (2016-2020) and included gestational age, birth anthropometrics, and age of thelarche and/or pubarche and/or menarche, along with corresponding anthropometric, hormonal, and biochemical measurements.

RESULTS

Data from 298 girls' medical records were included in the analysis. Median age at menarche, thelarche, and pubarche was 12, 9, and 9 years, respectively. The mean interval between pubertal onset and menarche was 1.99 years. The mean body mass index (BMI) at menarche and thelarche was 20.99 kg/m2 and 18.90 kg/m2, respectively. The mean weight at menarche was 49.6 kg, whereas the mean height difference between thelarche and menarche was 19.17 cm. Among participants, 6.3% had premature menarche, while 24.0% had premature thelarche. Birth weight was moderately correlated with BMI at thelarche/pubarche (rs=0.334, p = 0.005). Birth weight and BMI at thelarche/pubarche were not predictive of premature menarche or premature thelarche. Median (interquartile range, IQR) levels at menarche vs. thelarche were significantly higher for insulin-like growth factor-1 [358.00 (140.50) vs. 176.00 (55.00) ng/ml], follicle stimulation hormone [5.65 (3.14) vs. 3.10 (4.23) mIU/ml], testosterone [25.50 (31.00) vs. 13.00 (21.00) ng/dl], dehydroepiandrosterone sulfate [117.00 (112.50) vs. 46.40 (51.90) µg/dl], and insulin [17.40 (15.05) vs. 8.47 (4.97) µIU/ml].

CONCLUSION

The timing of pubertal stages in the Greek female sample studied followed the recent international downward trends. Younger age at menarche was not related to BMI.

Decline in pubertal timing and its relationship with excess weight. A study of the secular trend in age at menarche in girls from La Plata district (Buenos Aires, Argentina)

OBJECTIVE

To provide information on the secular trend in age at menarche (AgM) in Argentinean girls in relation to excess weight (EW) and body adiposity.

METHODS

Two cohorts (C) (C1, 2005-2007 and C2, 2015-2019) of children aged 8-14 years from La Plata district were studied using identical methodological criteria. Each participating child was asked about menarche (M) status: M presence (MP) or absence (MA). The AgM was estimated using the status quo method and logistic regression analysis. Body weight, height, and tricipital and subscapular skinfolds were collected to estimate EW (overweight + obesity) according to WHO criteria, and body adiposity (sum of skinfolds, SSK = [tricipital + subscapular]). The prevalence of EW by C was estimated and compared using the Chi-square test. The MP probability in relation to age, C, and EW was analyzed by applying logistic regression. Parents completed a questionnaire to assess family socioeconomic conditions. Data were compared using the Chi-square test.

RESULTS

Differences in MP prevalence between C were significant (C1: 21.1% vs. C2: 28.7%). Median AgM was 12.81 years in C1 and 12.22 in C2. The prevalence of EW was higher in C2 (35.3%) than in C1 (24.6%). The probability of MP was higher in C2 than in C1 and children with EW. Both BMI and SSK showed inter-cohort increases. Socioeconomic conditions were substantially deteriorated between C.

CONCLUSION

In an obesogenic context marked by the significant increase in body adiposity and EW, M prevalence exhibited a positive secular trend and AgM reduced by nearly seven months between the cohorts studied.

Earlier Menarche in Greek Girls Born by Caesarean Section: A Case-Control Study

Objectives: The purpose of this study was to report on the menarcheal age in girls of Greek origin and assess its potential associations with their demographic and perinatal data, as well as their maternal menarcheal age. Methods: In this case-control study, adolescent girls were recruited between September 2021 and September 2022 from two Pediatric Endocrinology Units, Aristotle University of Thessaloniki, Greece. Eligible participants included Greek girls up to the age of 18 years, with menarche and the absence of chronic disease or chronic medication use. Participants were divided into two groups, the early menarche group and the control group (menarche before or after 11 years of age, respectively). Data included participants' maternal menarcheal age, their chronological age, place of residence, anthropometric data (at recruitment) and perinatal data (birth order, gestational age, type of delivery, birth weight/length). Results: A total of 100 girls aged 7-17 years (mean age ± SD 12.51 ± 2.59 years) were included in this study. The mean ± SD menarcheal age of the total sample was 11.47 ± 1.55 years (median 11.20 years; range 7.50-16.25 years); 43% had early menarche (median menarcheal age 10.50 years; range 7.50-10.91 years), and 57% had menarche after age 11 (median menarcheal age 12.08 years; range 11.00-16.25 years). The caesarean section rate was significantly (p < 0.001) higher in girls with early menarche (83.7%) than controls, whereas other variables did not differ significantly between groups. Conclusions: This Greek sample demonstrated a relatively young age at menarche with a significant proportion of girls with early menarche; in the latter group, the rate of caesarian sections was significantly higher than controls.

Characterization of Puberty in an Australian Population-Based Cohort Study

PURPOSE

Current knowledge of the characteristics of puberty beyond age at menarche and thelarche is limited, particularly within population-based cohorts. Secular trends and concerns of the health effects of early puberty reinforce the value of contemporary studies characterizing the timing, tempo, duration, and synchronicity of puberty.

METHODS

The Childhood to Adolescence Transition Study is a unique Australian cohort of individuals followed annually from late childhood to late adolescence, with up to eight assessments of pubertal stage from 9 to 19 years of age (N = 1,183; 636 females). At each assessment, females reported their Tanner Stage of breast and pubic hair development, while males reported on genital/pubic hair development. Nonlinear mixed-effects models characterized pubertal trajectories and were used to derive each individual's estimates of timing, tempo, and synchronicity. Parametric survival models were used to estimate the overall duration of puberty.

RESULTS

Timing of mid-puberty (Tanner Stage 3) ranged from 12.5 to 13.5 years, with females developing approximately 6 months before males. Pubertal tempo (at mid-puberty) was similar across sex (between half and one Tanner Stage per year), but the overall duration of puberty was slightly shorter in males. Most females exhibited asynchronous changes of breast and pubic hair development.

DISCUSSION

Estimates of pubertal timing and tempo are consistent with reports of cohorts from two or more decades ago, suggesting stabilization of certain pubertal characteristics in predominantly White populations. However, our understanding of the duration of puberty and individual differences in pubertal characteristics (e.g., synchronicity of physical changes) remains limited.

The Effect of Growth and Body Surface Area on Cardiopulmonary Exercise Testing: A Cohort Study in Preadolescent Female Swimmers

BACKGROUND

The performance of young swimmers is the result of a multifactorial process that is influenced by anthropometric characteristics and biological maturation. The purpose of our study was to investigate the effect of stages of biological maturation and body surface area on cardiopulmonary fitness indicators in preadolescent female swimmers, for whom menstruation has not started.

METHODS

Thirty female preadolescent swimmers (age 13.4 ± 1.0 years) participated in this study. We recorded anthropometric and morphological characteristics, stages of biological maturation, and pulmonary function parameters, and the swimmers underwent cardiopulmonary exercise testing.

RESULTS

The cut-off was set for body surface area (BSA) at 1.6 m2 and for biological maturation stages at score 3. The BSA results showed differences in variabilities in maximal effort oxygen pulse (p < 0.001), oxygen uptake (p < 0.001), ventilation (p = 0.041), tidal volume (p < 0.001), and oxygen breath (p < 0.001). Tanner stage score results showed differences in variabilities in maximal effort breath frequency (p < 0.001), tidal volume (p = 0.013), and oxygen breath (p = 0.045). Biological maturation stages and BSA were correlated during maximal effort with oxygen breath (p < 0.001; p < 0.001), oxygen uptake (p = 0.002; p < 0.001), and oxygen pulse (p < 0.001; p < 0.001).

CONCLUSIONS

In conclusion, the findings of our study showed that the girls who had a smaller body surface area and biological maturation stage presented lower values in maximal oxygen uptake and greater respiratory work.

Ongoing increasing trends in central precocious puberty incidence among Korean boys and girls from 2008 to 2020

BACKGROUND

Over the last few decades, there has been growing evidence of earlier onset and progression of puberty worldwide. This population-based longitudinal cohort study aimed to analyze the change in the annual incidence rate of central precocious puberty (CPP) among Korean children over the most recent decade, using the national registry data.

METHOD

The International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) and insurance claims for gonadotropin-releasing hormone agonist (GnRHa) treatment were used to identify CPP patients who were using the Korean Health Insurance Review & Assessment Service (HIRA) database between 2008 and 2020. Patients who began GnRHa therapy before the age of 9 and 10 for girls and boys, respectively, were included in the study.

RESULTS

A total of 6,906 boys and 126,377 girls were diagnosed with CPP between 2008 and 2020. The annual incidence of CPP increased by 83.3 times in boys (from 1.2 to 100 per 100,000 persons) and by 15.9 times in girls (from 88.9 to 1414.7 per 100,000 persons). The age-specific annual incidence of CPP increased remarkably more in older children than in younger ones; the 2020 CPP incidence among 9-year-old boys and 8-year-old girls reached 705.2 and 7,967.3 per 100,000 persons, respectively. The annual prevalence of CPP in boys and girls increased from 2.7 to 206.5 (76.5 times) and from 141.8 to 3439.9 (24.3 times) per 100,000 persons, respectively.

CONCLUSION

Based on GnRHa treatment insurance claims, our study suggests that the annual incidence of CPP has substantially increased in Korea during the past 13 years. These findings highlight the importance of meticulous judgment by doctors in determining GnRHa treatment.

Age at Menarche, Growth Velocity, and Adiposity Indices in Italian Girls Aged 10 to 14

Age at menarche (AAM) is an effective marker of puberty timing but its onset could be influenced by several intrinsic and extrinsic factors. This study aimed to assess the AAM in a sample of Italian adolescents and to investigate its association with anthropometric variables. Considering the rise in overweight/obesity worldwide, special attention was paid to a possible decrease in AAM as adiposity indices increase. A longitudinal study was carried out on 117 middle school girls in Northern Italy. Data concerning menarche and anthropometric traits (standing and sitting height, weight, waist circumference, and skinfold thicknesses) were directly collected. Lower limb length and indices of adiposity and growth were calculated. The median AAM was 11.66 (95% IC: 11.31-11.68). Age-adjusted ANCOVA between mature and non-mature girls showed significant differences in growth-related traits and WHtR. No preponderance of overweight/obesity among mature participants was found. AAM was not significantly associated with weight or the growth velocity of adiposity indices in a subsample of maturers. Moreover, the median AAM of our sample was similar to that found in women born about 60 years ago in the same region. In conclusion, in addition to a stabilization of AAM since the 1960s, our results suggest that there is no significant correlation between increased adiposity and early AAM.

Trends Toward Earlier Puberty Timing in Girls and Its Likely Mechanisms

This is the first of two installments examining early puberty in girls. The first paper will discuss secular trends in onset of puberty and the possible mechanisms to explain these developments. The potential etiologies examined will include the role of endocrine-disrupting chemicals and obesogens, the impact of body mass index and obesity, genetic and biologic pathways, and the influence of lifestyle behaviors. The second paper of the two-part series will examine the potential health impacts of early puberty on young and adult women and offer suggestions for clinical management and public health prevention.

Earlier Age at Menarche Is Associated with Body Fat and Negative Body Image in Adult Life

Earlier age at menarche is one of the well-documented antecedents of a range of adverse health effects in adulthood including obesity and psychopathological effects. Yet, few researchers have examined the potential association of menarcheal age with body fat distribution, self-perception, and body image. We retrospectively tested a sample (N = 392) of adult women (18-80 years) to examine the associations of age at menarche with body composition and body image indices. Analyses of covariance and multivariable logistic and linear regression were fitted adjusting for age, physical activity level, smoking, and alcohol consumption. Further adjustment was made for body mass index (BMI) and percentage of fat mass. Earlier age at menarche was associated with slightly increased odds of higher BMI and abdominal fat percentage; of note is the positive correlation with lower body composition indices including hip and calf circumferences/skinfolds. Additionally, earlier age at menarche was associated with higher scores in the negative body image scales, namely overweight preoccupation and self-classified weight, whereas lower risks were found for higher scores in the positive body image scales, namely appearance evaluation and body area satisfaction scales. These findings remained significant after correcting for body fat percentage. The present results showed positive associations for earlier age at menarche with gross indices of obesity with the associations mainly confined to distribution of body fat in the lower part of the body, whereas an increased risk of negative body image was also found. Future research could refine our understanding of the biological and psychological mechanisms underlying these associations.

A secular trend in age at menarche in Yunnan Province, China: a multiethnic population study of 1,275,000 women

Background

Age at menarche (AAM) has shown different trends in women from different ethnic and economic regions in recent decades. Data on AAM among multiethnic women living in developing areas are scarce.

Methods

Data on AAM from 1,275,000 women among 26 ethnicities in Yunnan Province, China, who were born from 1965 to 2001 were obtained from the National Free Preconception Health Examination Project from 2010 to 2018. The patterns of AAM trends were analysed according to ethnic group, area of residence, and socioeconomic status.

Results

The mean AAM was 13.7 ± 1.21 years (95% CI 13.697–13.701), with a decrease from 14.12 (±1.41) among women born before 1970 to 13.3 (±1.04) among those born after 2000. The decline was 0.36 years per 10-year birth cohort, and the plateau has not yet been reached in Yunnan. A secular trend of earlier AAM was observed in all 26 ethnic groups. The fastest rate of decline was observed for the Bai ethnicity (0.36 years per decade). Consistent declining trends in AAM appeared among extreme-, middling-, and nonpoverty economic patterns from 1965 to 2001, with reductions of 1.19, 1.44, and 1.5 years, respectively (P < 0.001). The peak reduction among middling poverty and extreme poverty occurred in the early 2000s (0.4 and 0.32 years). Multivariate analysis showed a significant difference in the declining trends in AAM along rural/urban lines (P < 0.001).

Conclusion

There was a secular trend towards a younger AAM during the twentieth century and early twenty-first century birth cohorts in the Yunnan population. Considering the difference in AAM trends due to ethnic and socioeconomic status in Yunnan, the health authority should utilize flexible adjusted health care strategies in different regions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11951-x.

A Retrospective Long-Term Study on Age at Menarche and Menstrual Characteristics in 85 Young Women with Transfusion-Dependent β-Thalassemia (TDT)

BACKGROUND

Menarche is an important milestone in a feminine reproductive life, and regular menstrual cycles reflect normal functioning of the hypothalamic-pituitary-ovarian axis, a vital sign of women's general health.

AIM OF THE STUDY

We explored the age at menarche and the following menstrual cycles characteristics among 85 unmarried Transfusion-Dependent β-Thalassemia (TDT) women, born between 1965 and 1995, concerning iron chelation therapy (ICT) with desferrioxamine (DFO) and nutritional status, assessed by body mass index (BMI).

RESULTS

53 adolescents who had begun ICT before the age of 10 years experienced menarche at 13,7 ± 1,6 years (mean ± DS), whereas 32 who began treatment after ten years experienced menarche significantly later (15.5 ± 1.9 yrs; p: 0.001). At the age of menarche: BMI-Z score (n= 67, -0,09 ±1) was inversely correlated with both age at starting ICT (r = -0,39; p = 0001) and age at menarche (-0,45, p = 0,0001). Serum ferritin levels (SF) were significantly correlated with the age at starting chelation therapy (n = 79; r = 0,34; p = 0,022). In 56 TDT adolescents who developed secondary amenorrhea (SA), the SF levels were significantly higher (4,098 ± 1,907 ng/mL) compared to 23 TDT adolescents with regular menstrual cycles (2,913±782 ng/mL; p = 0,005). Nutritional status of "thinness" at menarche was associated with a lower prevalence of subsequent regular menstrual cycles and a higher prevalence of early SA.

CONCLUSION

An early ICT in TDT patients was associated with a normal "tempo" of pubertal onset and a higher frequency of subsequent regular menstrual cycles. In TDT patients, who developed SA, a diagnosis of acquired central hypogonadism was made, mainly due to the chronic exposure to iron overload, however other potential causes linked to nutritional status, deficient levels of circulating nutrients, and the chronic disease itself cannot be fully excluded.

Trend of Menarcheal Age among Korean Girls

BACKGROUND

Menarcheal 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.

METHODS

We 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.

RESULTS

Ninety-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.

CONCLUSION

We reported an ongoing downward trend in menarcheal age in Korean girls born in 1988-2003, decreasing by 0.4 years over the 15 years.

Growth and socio-economic status, influence on the age at menarche in school going girls

INTRODUCTION

Onset age at menarche has been considered an important indicator of reproductive maturity in females and reflects the health status of the population. The purpose of this study was to determine the mean menarcheal age and to examine whether anthropometric and socio-economic status (SES) influences age at menarche in the girls from Punjab province of Pakistan.

METHODS

In this population-based cross-sectional study, 10,050 school-going girls aged 8-16 years from 35 schools across 12 districts of Punjab were recruited. Menarcheal data was obtained by using a questionnaire, while the anthropometric data were obtained by the measurements of standing height, body weight, waist, and hip circumference. The anthropometric indices of pre- and post-menarcheal girls were compared. Student's t-test, ANOVA, and post-hoc Tukey's test was applied for comparison between two and multiple groups respectively, P < 0.05 was considered statistically significant.

RESULTS

There was a normal distribution of age at menarche and mean was 12.4 years in the study population. The girls who reached menarche were found to be taller and heavier with higher BMIs, having a greater waist and hip circumference as compared to their pre-menarcheal peers. Waist-hip-ratio was less, and the waist-to-height ratio was higher in post-menarcheal as compared to pre-menarcheal girls. The girls belonging to low SES had delayed onset of menarche as compared to those belonging to middle/high SES.

CONCLUSION

The age at menarche was associated with SES and changes in various anthropometric measurements reflecting the growth status of girls.

Menstrual Disorders and Androgen-Related Traits in Young Women with Type 1 Diabetes Mellitus: a Clinical Study

OBJECTIVE

To investigate possible causes of menstrual disorders and androgen-related traits in young women with type 1 diabetes mellitus (T1DM).

METHODS

Fifty-three women with T1DM (duration 8.0±5.6 years), 41 women with (polycystic ovary syndrome) PCOS, and 51 controls matched for age (19.4±4.3 years vs. 21.2±2.7 years vs. 20.8±3.1 years; P>.05) and body mass index (BMI) (22.2±2.7 kg/m2 vs. 21.9±2.0 kg/m2 vs. 21.4±1.9 kg/m2; P>.05) were prospectively recruited.

RESULTS

Two women (3.8%) in the T1DM group had not experienced menarche (at 15.5 and 16.6 years); of the rest, 23.5% had oligomenorrhea, 32.1% hirsutism, and 45.3% had acne. The age at menarche was delayed in the T1DM group compared to controls (12.7±1.3 vs. 12.0±1.0 years; P = .004), while no difference was observed with the polycystic ovary syndrome (PCOS) group (12.4±1.2 years). There were no differences in total testosterone (0.43±0.14 ng/mL vs. 0.39±0.14 ng/mL; P>.05), dehydroepiandrosterone sulfate (DHEA-S) (269 ± 112 μg/dL vs. 238 ± 106 μg/dL; P>.05) or Δ4-androstenedione (2.4±1.3 ng/mL vs. 1.9±0.5 ng/mL; P>.05) concentrations between T1DM and controls. However, patients with T1DM had lower sex hormone binding globulin (SHBG) concentrations than controls (61 ± 17 nmol/L vs. 83 ± 18.1 nmol/L; P = .001), which were even lower in the PCOS group (39.5±12.9 nmol/L; P = .001 compared with T1DM). The free androgen index (FAI) was higher in the PCOS group compared with both other groups (T1DM vs. PCOS vs. controls: 2.53±0.54 vs. 7.88±1.21 vs. 1.6 ± 0.68; P<.001). FAI was higher in patients with T1DM compared to controls as well (P = .038). There was no difference in DHEA-S concentrations between T1DM and PCOS patients (269 ± 112 μg/dL vs. 297 ± 100 μg/dL; P>.05).

CONCLUSION

Menstrual disorders and androgen-related traits in young women with T1DM may be attributed to an increase in androgen bioavailability due to decreased SHBG concentrations.

Menarche at an Earlier Age: Results from Two National Surveys of Israeli Youth, 2003 and 2016

STUDY OBJECTIVE

To assess emergent changes in the age at menarche and investigate associated factors in Israeli adolescents in 2003 and 2016.

DESIGN

Cross-sectional study.

SETTING

Two national representative school-based surveys (first and second "Mabat Youth").

PARTICIPANTS

Both surveys included female students in 7th-12th grades (ages 11-19 years). The first (N = 3328) was conducted between the years 2003 and 2004, and the second (N = 2535) from 2015 to 2016.

INTERVENTIONS

The survey questionnaire was self-administered and anthropometric measurements were performed by trained personnel.

MAIN OUTCOME MEASURES

The current age at menarche in Israeli girls was determined and independent factors (demographic, clinical, and lifestyle) examined. Changes that occurred since the past national survey more than a decade ago were documented.

RESULTS

The estimated median age at menarche declined from 13.0 (interquartile range, 12.0-14.0) years in 2003-2004 to 12.5 (interquartile range, 12.0-13.0) years in 2015-2016 (P < .0001). Jewish girls reached menarche earlier than Arab girls, but both populations experienced a similar downward trend in the past approximately 14 years. Greater body mass index, higher socioeconomic status, and immigrant status were associated with younger menarche onset (P < .001). Age at menarche remained lower in 2015-2016 vs 2003-2004, even after adjustment for these potential confounders, with a high hazard ratio (HR), which decreased as a function of survival time (t): HR_t = 15.417 × 0.813^t.

CONCLUSION

This study confirms the decline in age at menarche in Israel. Findings were associated with body mass index and population group but also indicated that other factors are likely involved.

Outcomes of pregnancies in patients with Gaucher Disease: The experience of a center of excellence on rare metabolic Disease-Gaucher Disease, in Greece

OBJECTIVE

Pregnancy is reported to exacerbate manifestations in women with Gaucher Disease (GD). The objective of our study was to examine the outcome of pregnancies of Caucasian women with GD in a Greek Center of Excellence on GD.

STUDY DESIGN

Fifteen GD women were enrolled. All data were collected by questionnaire: fertility, normal pregnancies, spontaneous-elective-therapeutic abortions, maternal -neonatal status, birth weight and chromosomal abnormalities.

RESULTS

Forty-one pregnancies were reported among 15 women: mean conception age (±SD) 27.7 ± 5.8years (range 17-42years). Thirty-seven conceptions were spontaneous, 4 were after in vitro fertilization (IVF). Twenty three out of the 41 (56.1 %) pregnancies were normal. Eleven out of the 41 (26.8 %) pregnancies resulted in spontaneous abortions, 3 out of 41 (7.3 %) in elective and 3 out of 41 (7.3 %) in therapeutic abortions. Therapeutic abortions were due to worsening of GD manifestations, fetal chromosomal abnormalities and GD type 2 embryo. Nine out of 15 women had maternal complications: gestational diabetes, splenomegaly, hepatomegaly, thrombocytopenia, osteoporosis and postpartum hemorrhage. Twenty three out of the 41 pregnancies resulted in live births. Nine out of the 23 (39.1 %) deliveries were caesarian sections and 14 out of 23 (60.9 %) were vaginal. The total number of neonates was 24 (14 females / 10 males). Mean gestational age on delivery (± SD) was 35.9 ± 3.1 weeks (range 26-38 w). Average female birth weight (±SD) was 2671.4 ± 851.6 g (range 900-4100 grams) and male was 3333 ± 996.4 g (range 1930-4700 grams). Nine out of 24 (37.5 %) neonates had low birth weight. Average low birth weight (±SD) was 1931.1 ± 420.52 g (range 900-2300 grams). Twenty out of the 24 (83.3 %) neonates were healthy. Four out of 24 neonates had neonatal complications: two neonates had GD type 1, one had GD type 3 and one neonate died two days after delivery (it was born at 26 weeks). Four neonates were hospitalized in incubators at the intensive neonatal care unit due to low birth weight. Thirty-nine women did not receive enzyme replacement therapy for GD during pregnancy, while, in two pregnancies, treatment was discontinued during the first trimester and re-administered after that. Mean first menarche age (±SD) was 13.6 ± 0.7 years. Thirteen out of 15 women were menopausal, mean menopausal age (± SD) 466 ± 2.6 years.

CONCLUSION

Most of GD women experience uncomplicated pregnancies and deliver normal, healthy infants, although the rate of complications and the rate of abortions is high in this population.

Common Genetic Influences on Age at Pubertal Voice Change and BMI in Male Twins

The present study aimed to explore secular trends in age at voice change (AVC), estimate heritability of AVC and investigate to what extent common genes influence the association between AVC and body mass index (BMI) in South Korean males. The sample of 955 male twins consisted of 241 pairs and 118 co-twin missing monozygotic (MZ) twins, 82 pairs and 50 co-twin missing dizygotic (DZ) twins and 141 male members of opposite-sex DZ twins who participated in telephone surveys in the South Korean Twin Registry. AVC was asked of twins during the surveys. The mean (SD) age of the sample was 18.92 (2.42) years (range: 16.00-29.25 years). The birth years of the twins were divided into two groups (1988-1993, 1994-2001). Kaplan-Meyer survival analyses were conducted to compute the mean age of AVC in the total sample as well as to test mean differences between the two birth cohorts. Maximum likelihood twin correlations and univariate and bivariate model-fitting analyses were performed. The mean AVC in the total sample was 14.19 (95% CI [14.09, 14.29]) years. The mean AVC significantly declined from 14.38 to 14.02 years from 1988 to 2001, confirming downward trends in AVC in recent years. Heritability for AVC was .59 (95% CI [.50, .67]), which was within the range reported in most Western twin studies. Although the phenotypic correlation between AVC and BMI was modest (r = -.14; 95% CI [-.07, -.21]), it was entirely mediated by common genes, similar to what has been found in females in prior twin studies. In conclusion, the present twin study underscores the importance of genetic influences on pubertal timing and its association with BMI in South Korean males.

Indicators of nutritional status and physical activity level as factors associated with the onset of menarche of ten year old girls from Zadar county, Croatia

OBJECTIVES

The aim is to determine the differences in nutritional status and level of physical activity (PA) of ten year old menstruating and non-menstruating girls.

METHODS

On the sample of 208 girls, fourth graders of elementary schools in Croatia, the indicators of nutritional status were measured: body mass index(BMI), body fat % and waist to hip ratio(WHR), while the PA was assessed using PAQ-C questionnaire. Welch´s t-test was applied to establish the differences and multivariate regression analysis was applied to establish the relationships.

RESULTS

Menstruating girls have significantly higher body mass (43.42 kg±8.31 vs. 38.64 kg±8.33), waist circumference (68.10 cm ± 9.86 vs. 62.22 cm ± 7.16), hip circumference (80.81 cm ± 7.24 vs. 76.63 cm ± 7.7), BMI (19.70 ± 3.42 vs. 17.74 ± 3.10), body fat % (28.05 ± 7.54 vs. 21.98 ± 7.67) and WHR (0.84 ± 0.06 vs. 0.81 ± 0.05) in comparison to non-menstruating girls, while non-menstruating girls have significantly higher PA level (2.93 ± 0.57 vs. 2.68 ± 0.57). The regression analysis have shown a significant relationship between body fat % and the onset of menarche (β=-0.23, SEβ=0.07, p<0.01).

CONCLUSIONS

Results show differences in the indicators of nutritional status of girls with regard to the status of maturity. Increased nutritional status and body fat % may be indicators of the accelerated developmental tempo and a determinant for the earlier onset of menarche.

The levelling-off of the secular trend of age at menarche among Italian girls

OBJECTIVE

The main aim of this study was to verify whether the secular trend stopped in Italy by comparing the results of a 1990-2000 birth cohort versus a 1980-1990 birth cohort of Italian young women. The results were used to speculate about age at menarche as adaptive response to non-genetic factors.

METHODS

In 2016, a study was set on 413, 18-to-26 year-old women (1990-2000 birth cohort) attending two Italian Universities by web-based, self-reported questionnaires. Previously in 2000, a research including 3,783 high school female students (1980-1990 birth cohort) was led. The age at menarche distribution was performed by Kaplan-Meier analysis. The comparison between the findings of the two birth cohorts was performed by Wilcoxon sum-rank test. Mixed models analysis was applied to evaluate the effect of cohort and socio-economic status on age at menarche.

RESULTS

1990-2000 cohort's age at menarche median was 12.44y (95%CI 12.37; 12.59y). There was no significant difference with age at menarche of the previous cohort (p = 0.56). Consistently, the advance of age at menarche in comparison to the mothers' one was not significantly different between the two cohorts (-0.27y±0.10y vs -0.25y±0.03y, p = 0.33). The socio-economic level was not significantly associated with menarcheal age.

CONCLUSIONS

The findings of this study confirm that, like in other developed countries, the advance of age at menarche has stopped in Italy, consistently with the stop of the improvement of socio-economic conditions. Further studies are needed to explore the differential effect of each non-genetic factor to outline future scenarios of human sexual maturation.

TRIAL REGISTRATION

the Comitato Etico per la Sperimentazione Clinica (CESC) della Provincia di Padova of the Veneto Region (Italy), n°3993/U16/16.

Heritability of Age at Menarche in South Korean Female Twins

Genetic and environmental influences on age at menarche (AAM) have rarely been examined in Asian females. This study aimed to investigate the heritability of AAM in South Korean female twins. The AAM data from 1370 female twins (933 monozygotic [MZ] twins, 294 dizygotic [DZ] twins and 160 female members of opposite-sex DZ twins) born between 1988 and 2001 were analyzed. The age of the sample at the time of the assessment ranged from 16 to 28 years with a mean of 19.3 (SD = 2.2) years. The mean AAM in the total sample was 12.49 (SD = 1.41) years. Although the mean AAM decreased with increasing birth years, it levelled off in birth years 2000-2001. Maximum likelihood MZ and DZ twin correlations were 0.72 [95% CI (0.67, 0.76)] and 0.35 [95% CI (0.19, 0.50)], respectively. The results of model-fitting analysis indicated that the additive genetic and individual-specific environmental effects were 72% [95% CI (67%, 76%)] and 28% [95% CI (24%, 33%)], respectively. Neither nonadditive genetic nor shared environmental effects were significant.

Systematic review and meta-analysis of the association between childhood physical activity and age at menarche

AIM

To systematically appraise and summarise published evidence on the association between childhood physical activity (PA) and subsequent age at menarche (AAM).

METHODS

We searched PubMed (1990-2018) for studies that reported the relationship between childhood PA and AAM. We performed tabular synthesis of population-based studies and a random-effects meta-analysis of results of athlete/nonathlete studies.

RESULTS

One randomised controlled trial was identified, in which an intervention to prevent obesity reduced the likelihood of menarche during the two-year study period (relative risk: 0.75, 95% CI: 0.66-0.87; n = 422 girls). One of five prospective cohort studies (total n = 4492) reported a significant association between self-reported PA duration and subsequent menarche timing. Four of five historical cohort studies (total n = 89 470) reported significant associations between recalled premenarcheal PA and later AAM. Meta-analysis across 12 athlete/nonathlete studies showed that menarche occurred 1.13 years later (95% CI: 0.80-1.47) in athletes compared to nonathletes.

CONCLUSION

These findings suggest that AAM is a behaviourally modifiable trait. However, the quality of reported population-based study evidence is low and estimation of the true relationship between childhood PA and AAM is likely confounded by concomitant changes in diet and lifestyle behaviours.

MKRN3 Mutations in Central Precocious Puberty: A Systematic Review and Meta-Analysis

MKRN3 mutations represent the most common genetic cause of central precocious puberty (CPP) but associations between genotype and clinical features have not been extensively explored. This systematic review and meta-analysis investigated genotype-phenotype associations and prevalence of MKRN3 mutations in CPP. The search was conducted in seven electronic databases (Cochrane, EMBASE, LILACS, LIVIVO, PubMed, Scopus, and Web of Science) for articles published until 4 September 2018. Studies evaluating MKRN3 mutations in patients with CPP were considered eligible. A total of 22 studies, studying 880 subjects with CPP, fulfilled the inclusion criteria. Eighty-nine subjects (76 girls) were identified as harboring MKRN3 mutations. Girls, compared with boys, exhibited earlier age at pubertal onset (median, 6.0 years; range, 3.0 to 7.0 vs 8.5 years; range, 5.9 to 9.0; P < 0.001), and higher basal FSH levels (median, 4.3 IU/L; range, 0.7 to 13.94 IU/L vs 2.45 IU/L; range, 0.8 to 13.70 IU/L; P = 0.003), and bone age advancement (ΔBA; median, 2.3 years; range, -0.9 to 5.2 vs 1.2 years; range, 0.0 to 2.3; P = 0.01). Additional dysmorphisms were uncommon. A total of 14 studies evaluating 857 patients were included for quantitative analysis, with a pooled overall mutation prevalence of 9.0% (95% CI, 0.04 to 0.15). Subgroup analysis showed that prevalence estimates were higher in males, familial cases, and in non-Asian countries. In conclusion, MKRN3 mutations are associated with nonsyndromic CPP and manifest in a sex-dimorphic manner, with girls being affected earlier. They represent a common cause of CPP in western countries, especially in boys and familial cases.

Menstrual abnormalities and their association with lifestyle pattern in adolescent girls of Garhwal, India

BACKGROUND

This study tried to find out the prevalence of menstrual abnormalities in adolescent girls and their association with dietary and exercise pattern in Garhwal region of India.

MATERIALS AND METHODS

In this study, cross-sectional questionnaires survey was conducted in different schools of Garhwal. These questionnaires were based on socioeconomic data, dietary and physical activities, and menstrual abnormalities.

RESULTS

The age of menarche was 13.5 ± 0.64 years. Dysmenorrhea (62.75%), premenstrual syndrome (PMS) (40.42%), and irregular cycle (28.72%) were observed common problems among adolescent girls. The result showed that dysmenorrhea, PMS, and menstrual irregularities were directly associated with dietary habits and physical activities. Dysmenorrhea was associated with eating junk food (66.10%), and PMS was associated with lacking of physical activities (78.94%).

CONCLUSION

The result suggests that feeding habit and physical activities directly affecting the menstrual health of adolescent girls.

Secular Trend of Age at Menarche in Chinese Adolescents Born From 1973 to 2004

OBJECTIVES

To estimate secular trend and factors influencing the age at menarche for Chinese girls born from 1973 to 2004.

METHODS

Data were collected from the China Health and Nutrition Survey, a prospective open cohort and an ongoing nationwide health and nutrition survey, consisting of 3199 apparently healthy Chinese girls aged 6 to 18 years at entry from 1991 to 2011. Average age at menarche and its 95% confidence interval were estimated by weighted means of Kaplan-Meier survival analysis. Cox proportional hazard models were applied to identify the independent predictive factors of age at menarche.

RESULTS

The age at menarche declined from 14.25 in Chinese girls born before 1976 to 12.60 in girls born after 2000, with an estimated decline of 0.51 years per decade (P < .001). The downward trend of age at menarche for rural girls was greater than for urban girls (0.62 vs 0.35 years per decade; P < .001). Girls living in urban areas, living in central areas, with high BMI, and with high-energy diets had a high risk of early menarche, whereas girls living on the east coast who had high-carbohydrate diets had a low risk of early menarche.

CONCLUSIONS

The authors of this study found a continuous downward secular trend of age at menarche for Chinese girls in both urban and rural areas born from 1973 to 2004. Among all variables, urban residency, BMI, and energy intake are negatively associated with age at menarche, whereas carbohydrate intake is positively associated with age at menarche.

The Evolution of the Age at Menarche from Prehistorical to Modern Times

Menarche denotes the onset of the female reproductive capacity. The age that menarche occurs is mostly attributed to the interaction of genetics and various environmental factors. Herein, the author describes the evolution of the age at menarche from prehistoric to the present times. Data from skeletal remains suggest that in the Paleolithic woman menarche occurred at an age between 7 and 13 years, early sexual maturation being a trade-off for reduced life expectancy. In the classical, as well as in the medieval years, the age at menarche was generally reported to be at approximately 14 years, with a range from 12 to 15 years. A significant retardation of the age at menarche occurred in the beginning of the modern times, soon after the industrial revolution, due to the deterioration of the living conditions, with most studies reporting menarche to occur at 15-16 years. In the 20th century, especially in the second half of it, in the industrialized countries, the age at menarche decreased significantly, as a result of the improvement of the socioeconomic conditions, occurring at 12-13 years. In the present times, in the developed countries, this trend seems to slow down or level off.

Age at menarche in Korean adolescents: trends and influencing factors

Background

An increased incidence of central precocious puberty has been recently reported in South Korea, which suggests an ongoing downward trend in pubertal development in the Korean population. We aimed to verify the trend in age at menarche in young Korean women during the last decade and associated factors.

Methods

We analyzed a population-based sample of 3409 Korean girls, aged 10–18 years, using data from the Korean National Health and Nutrition Examination Surveys (KNHANES) II (2001), III (2005), IV (2007–2009), and V (2010 and 2011). Average age at menarche was studied using the Kaplan-Meier survival method and predictors were analyzed using Cox proportional hazards model. The percentage of subjects who had experienced menarche at each age level was compared by using the Cochran-Armitage test.

Results

Overall mean age at menarche was 12.7 years. The percentage of subjects who experienced menarche before the age of 12 years was 21.4 % in 2001 but increased to 34.6 % in 2010/2011 (p < 0.01). In addition, the percentage of girls who experienced menarche before the age of 14 years increased from 76 % in 2001 to 92 % in 2010/2011 (p < 0.005). Adolescents whose mothers who had experienced early menarche (HR 1.48, 95 % CI [1.22–1.80]), and adolescents who were overweight (HR 1.24, 95 % CI [1.04–1.49]) were more likely to have experienced menarche. Additionally, underweight adolescents (HR 0.27, 95 % CI [0.12–0.60]) and adolescents who had a mother having late menarche (HR 0.68, 95 % CI [0.59–0.79]) were expected to have late menarche. None of the socioeconomic factors assessed in our study showed an association with age at menarche.

Conclusions

A downward trend in age at menarche was defined in Korean adolescents during the last decade. Furthermore, influences of genetic and nutritional parameters on individual variance in age at menarche were defined.

Secular trends in age at menarche among women born between 1955 and 1985 in Southeastern China

Background

Improvements in socioeconomic conditions and population health have been linked to declining age at menarche. In China, secular trends in age at menarche following extensive economic reform during recent decades have not been thoroughly investigated. This study examined the overall trend in age at menarche and assessed differences in the rate of change of age at menarche over time, and between urban and rural populations and education levels in southeastern China.

Methods

Age at menarche was retrospectively collected from 1,167,119 Han Chinese women born 1955–1985, who registered in the Perinatal Health Care Surveillance System in 19 cities and counties in two southeast provinces during 1993–2005. Multivariable linear regression was used to estimate trends in age at menarche overall and stratified by urban/rural residence and education level.

Results

Age at menarche declined by 0.33 [95% CI 0.33, 0.32] years/decade overall, with the fastest decline in women born in 1966–1975. For the earliest birth cohorts (1955–1965), age at menarche declined faster in urban versus rural regions, and for women with high school education or above versus primary school or less. In contrast, age at menarche declined slower among urban women born 1976–1985, and among those with higher education born 1966–1985.

Conclusions

Mean age at menarche declined for women born in 1955–1985 in southeast China. Further study is warranted to identify specific factors contributing to earlier age at menarche and associated health outcomes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12905-014-0155-0) contains supplementary material, which is available to authorized users.

Onset of menstrual cycle and menses features among secondary school girls in Italy: A questionnaire study on 3,783 students

PREMISE

Healthcare professionals need updated information about what is the range of "normal" variation of menstrual cycle features to support young girls and their parents in managing reproductive health, and to detect diseases early.

MATERIALS AND METHODS

This cross-sectional study aimed to provide an updated picture of age at menarche and main menstrual cycle characteristics and complaints in an Italian population-based sample of 3,783 adolescents attending secondary school. Girls filled in a self-administered anonymous questionnaire including questions about demography, anthropometry, smoking and drinking habits, use of contraceptive, socioeconomic status, age at menarche, menstrual pattern, and physical/psychological menstrual complaints. Mean age at menarche and prevalence of polymenorrhea (cycle length < 21 days), oligomenorrhea (cycle length > 35 days), irregularity, dysmenorrhea, and of physical/psychological complaints were computed. Factors associated with age at menarche and menstrual disturbances were explored by using multiple logistic models.

RESULTS

The girls' mean age was 17.1 years (SD 1.4 years) and the mean age at menarche was 12.4 years (SD 1.3 years); menarche occurred with two monthly peaks of frequency in July-September and in December-January (P < 0.0001). Age at menarche was significantly associated with geographic genetics (as expressed by parents' birth area), mother's menarcheal age, BMI, family size, and age at data collection. The prevalence of polymenorrhea was about 2.5%, oligomenorrhea was declared by 3.7%, irregular length by 8.3%, while long bleeding (>6 days) was shown in 19.6% of girls. Gynecological age was significantly associated with cycle length (P < 0.0001) with long cycles becoming more regular within the fourth year after menarche, while frequency of polymenorrhea stabilized after the second gynecological year. Oligomenorrhea and irregularity were both significantly associated with long menstrual bleeding (adjusted OR = 2.36; 95% CI = 1.55-3.60, and adjusted OR = 2.59; 95% CI = 1.95-3.44, respectively).

CONCLUSIONS

The findings of the study support the levelling-off of secular trend in menarche anticipation in Italy and confirm the timing in menstrual cycle regularization. The study provides updated epidemiological data on frequency of menstrual abnormalities to help reproductive health professionals in managing adolescent gynecology.

The role of early life nutrition in programming of reproductive function

Accumulating evidence suggest that the concept of programming can also be applied to reproductive development and function, representing an ever expanding research area. Recently issues such as peri- or even preconceptional nutrition, transgenerational effects and underlying mechanisms have received considerable attention. The present chapter presents the existed evidence and reviews the available data from numerous animal and human studies on the effects of early life nutritional environment on adult reproductive function. Specific outcomes depend on the severity, duration and stage of development when nutritional perturbations are imposed, while sex-specific effects are also manifested. Apart from undernutrition, effects of relative overnutrition as well as the complex interactions between pre- and postnatal nutrition is of high importance, especially in the context of our days obesity epidemic. Mechanisms underlying reproductive programming are yet unclear, but may include a role for epigenetic modifications. Epigenetic modulation of critical genes involved in the control of reproductive function and potential intergenerational effects represent an exciting area of interdisciplinary research toward the development of new nutritional approaches during pre- and postnatal periods to ensure reproductive health in later life.

Age at menarche in the Korean female: secular trends and relationship to adulthood body mass index

PURPOSE

The objective of this study is to estimate the trend in age at menarche in the Korean female and evaluate the relationship between age at menarche and adult body mass index (BMI), which is a indicator of later-life health.

METHODS

We conducted a cross-sectional analysis of a nationally representative sample (self-reported age at menarche and measured height and weight) of 11,065 females aged 15 and older. Data were obtained from the Fourth Korea National Health and Nutrition Examination Survey (KNHANES IV, 2007-2009).

RESULTS

We found a statistically significant decline in age at menarche in successive birth groups, indicating a 0.726 year decrease per decade. The age at menarche in 1990-1994 year birth group was 12.60 years, which showed a significant decreased from 3.11 years in the 1980-1984 birth group. We also found a significant negative association between age at menarche and current BMI. A one-year decrease in age at menarche was associated with mean BMI increase of 0.109 kg/m(2) (95% confidence interval [CI], 0.069 to 0.150) after adjustment for age. In multivariate logistic regression, the odds ratios of obesity in females with early menarche (<12 years) was 1.845 fold (95% CI, 1.441 to 2.361).

CONCLUSION

We found that age at menarche is still falling in the Korean female. We also found that early menarche is a risk factor for obesity in adults.

Age at menarche and its relationship to body mass index among adolescent girls in Kuwait

Background

Despite the increasing rates of childhood obesity and rapid change in socio-economic status, the mean age at menarche remains mostly unknown among contemporary girls in Kuwait and other countries in the Gulf region. This study aimed to estimate the mean age at menarche among schoolgirls in Kuwait and investigate the association between age at menarche and obesity.

Methods

A cross-sectional study was conducted on 1,273 randomly selected female high school students from all governorates in Kuwait. Overweight was defined as higher than or equal to the 85th percentile and obesity as higher than or equal to the 95th percentile using growth charts provided by the Centres for Disease Control and Prevention (CDC, 2000). Data on menarche, socio-demographic status, physical activity and diet were collected using confidential self-administered questionnaire.

Results

Out of 1,273 students, 23 (1.8%) were absent or refused to participate. The mean age at menarche was 12.41 years (95% CI: 12.35-12.48). The prevalence of early menarche, defined as less than 11 years of age, was 8.5% (95% CI: 7.0-10.2%). The prevalence of obesity and overweight was 18.3% (95% CI: 16.2-20.6%) and 25.8% (95% CI: 23.42-28.30%), respectively. Age at menarche was inversely and significantly associated with odds of overweight and obesity after adjusting for potential confounders, odds ratio 0.84 (0.77-0.93); (p = 0.001).

Conclusion

Age at menarche among contemporary girls in Kuwait is similar to that in industrialized countries. There is an inverse association between age at menarche and obesity or overweight. Trends in menarcheal age should be monitored and time of sexual maturation and its related factors should be taken into account in strategies that aim to combat obesity.

The relationship between malocclusion and menarcheal age, and its secular trend for Korean women

Objective

This study aimed to evaluate the mean age of menarche, its secular trend in Korean women, and the relationship between malocclusion and the rate of skeletal maturation, as defined by menarcheal age.

Methods

We retrospectively collected data on menarcheal age from 931 Korean women born during 1961 - 1997. Subjects were divided by the malocclusion type and birth-year decade into 3 and 4 groups, respectively. The mean menarcheal age for each group was determined, and one-way ANOVA was performed for intergroup comparison (p = 0.05). Two-way ANOVA was also performed to compare all the 12 subgroups (p = 0.05).

Results

The mean age of menarche was 12.82 years for Korean women born during 1961 - 1997. A distinct downward secular trend of menarcheal age was noticed (p < 0.05). For the birth-year decade 1961 - 1970, the Class III malocclusion group showed earlier onset of menarche than the other malocclusion groups (p < 0.05), but the other birth-year groups did not show any significant difference in the type of malocclusion (p > 0.05).

Conclusions

A positive secular trend towards earlier menarche exists among Korean women. Malocclusion does not show any significant relationship with the rate of skeletal maturation, as defined by menarcheal age.

National estimates of the pubertal milestones among urban and rural Chinese girls

PURPOSE

To provide clinically meaningful, normative reference data that describe pubertal timing indicators among urban and rural Chinese girls.

METHODS

Girls of Chinese Han ethnicity from grade 1 in elementary schools through grade 12 in junior high schools in eight regions participated in China Puberty Research Collaboration from October 2010 to May 2011. At examination, stages of breast and pubic hair development were assessed by trained physicians. Data on menses were collected through questionnaire survey.

RESULTS

A total of 15,388 girls aged 6.0-18.9 years participated in this collaboration study. Among them, approximately 53.5% (8,238) came from rural areas. The median ages at stage 2 of breast development of Chinese girls were 9.18 (95% confidence interval: 8.91-9.44) years and at stage 2 for pubic hair growth were 11.65 (95% confidence interval: 11.41-11.90) years. Girls with body mass index ≥85th percentile had earlier age for B2 (Tanner stage 2 for breast development), B3 (Tanner stage 3 for breast development), PH2 (Tanner stage 2 for pubic hair development), PH3 (Tanner stage 3 for pubic hair development), and menarche compared with girls with body mass index < 85th percentile. Urban girls achieved PH2, PH3, and menarche at a much earlier age than rural girls, except for B2 and B3 attainment. Mean menarcheal age is 12.43 years.

CONCLUSIONS

This study presented up-to-date data on female pubertal timing in a national sample of Chinese Han ethnicity girls and separately for urban and rural areas.

Determinants of menarche

Menarche is a milestone in a woman's life as it denotes the start of reproductive capacity. Aim of this report is to review the recent developments and the current knowledge in the neuroendocrinology of pubertal onset and the factors, genetic and environmental, that influence menarcheal age. We also review the implications of early or late menarcheal age on a young woman's life.

Update on age at menarche in Italy: toward the leveling off of the secular trend

PURPOSE

To update the information on age at menarche in the Italian population and to verify the influence of genetic, nutritional, and socioeconomic factors on menarcheal age. Recent studies suggest that the magnitude of the secular trend toward an earlier age at menarche is slackening in industrialized countries.

METHODS

This multicenter study was conducted on a large, population-based sample of Italian high school girls (n = 3,783), using a self-administered questionnaire. The questionnaire was used to gather information on the girls, including demography, anthropometry, menarcheal date, regularity of menses, behavioral habits, and physical activity. The questionnaire was also used to gather information on parents, including demography and mothers' and sisters' menarcheal ages. The median age at menarche and its 95% confidence interval were estimated by means of Kaplan-Meier survival analysis. To identify the independent predictive factors of age at menarche, multivariate mixed-effects models were applied.

RESULTS

The median age at menarche of the subjects was 12.4 years (95% confidence interval: 12.34-12.46). The girls had their first menses approximately one-quarter of a year (median-0.13) earlier than did their mothers (p < .0001). Among all variables, parents' birth area, body mass index, family size, and the mother's menarcheal age were significantly and independently associated with age at menarche.

CONCLUSIONS

This study confirmed the reduction in the trend toward earlier menarche in Italy. The results also confirmed that genetic and nutritional factors are strong markers for early menarche. Currently, socioeconomic factors do not seem to play as significant a role as in the past.

Age at menarche in a Korean population: secular trends and influencing factors

This study was designed to identify the secular trend in the age at menarche and to investigate the possible factors that influence the age at menarche using representative Korean data from the 2005 Korean National Health and Nutrition Survey. Three thousand five hundred sixty-two women born between 1920 and 1985 were enrolled to identify secular trends in the age at menarche and 620 girls born between 1986 and 1995 were recruited to evaluate the factors influencing the age at onset of menarche. Mean age at menarche decreased from 16.90 +/- 1.25 years for women born between 1920 and 1925 to 13.79 +/- 1.37 years for those born between 1980 and 1985, indicating a downward trend of 0.68 years per decade (95% CI, 0.64-0.71) in age at menarche. Mean age at menarche of girls born between 1986 and 1995 was 13.10 +/- 0.06 years as estimated by the Kaplan-Meier method. Among girls born between 1986 and 1995, menarcheal girls had a larger waist circumference, a higher body mass index (BMI), and lower maternal menarcheal age and maternal age at birth than premenarcheal girls. The energy and nutrient intake of protein, sugar, fiber, ash, phosphate, natrium, thiamine, riboflavin, and niacin were greater for menarcheal girls than for premenarcheal girls. These data indicate a decreasing secular trend of age at menarche in a Korean population born between 1920 and 1995. Furthermore, maternal menarcheal age, BMI, maternal age at birth, and nutrition are important variables that appear to influence age at menarche in Korean girls.

Pre- and postnatal nutritional histories influence reproductive maturation and ovarian function in the rat

BACKGROUND

While prepubertal nutritional influences appear to play a role in sexual maturation, there is a need to clarify the potential contributions of maternal and childhood influences in setting the tempo of reproductive maturation. In the present study we employed an established model of nutritional programming to evaluate the relative influences of prenatal and postnatal nutrition on growth and ovarian function in female offspring.

METHODS

Pregnant Wistar rats were fed either a calorie-restricted diet, a high fat diet, or a control diet during pregnancy and/or lactation. Offspring then were fed either a control or a high fat diet from the time of weaning to adulthood. Pubertal age was monitored and blood samples collected in adulthood for endocrine analyses.

RESULTS

We report that in the female rat, pubertal timing and subsequent ovarian function is influenced by the animal's nutritional status in utero, with both maternal caloric restriction and maternal high fat nutrition resulting in early pubertal onset. Depending on the offspring's nutritional history during the prenatal and lactational periods, subsequent nutrition and body weight gain did not further influence offspring reproductive tempo, which was dominated by the effect of prenatal nutrition. Whereas maternal calorie restriction leads to early pubertal onset, it also leads to a reduction in adult progesterone levels later in life. In contrast, we found that maternal high fat feeding which also induces early maturation in offspring was associated with elevated progesterone concentrations.

CONCLUSIONS

These observations are suggestive of two distinct developmental pathways leading to the acceleration of pubertal timing but with different consequences for ovarian function. We suggest different adaptive explanations for these pathways and for their relationship to altered metabolic homeostasis.