OBJECTIVE Younger age at menarche (AAM) may put girls at risk for earlier first sexual intercourse (FSI). Young age at FSI has far-reaching negative outcomes. We describe the longitudinal relationship between AAM and FSI in a large prospective birth cohort. METHODS AAM was collected from 554 girls from the Western Australia (Raine) Pregnancy Cohort Study, prospectively from age 10 or retrospe...

CONTEXT Age at menarche (AAM) is an important trait both biologically and socially, a clearly defined event in female pubertal development, and has been associated with many clinically significant phenotypes. OBJECTIVE The objective of the study was to identify genetic loci influencing variation in AAM in large population-based samples from three countries. DESIGN/PARTICIPANTS Recalled AAM ...

PURPOSE The study of the relationship ,between the age at menarche and socioeconomic status in a rural area in Sudan. WORK METHOD This was a cross-sectional descriptive study conducted in Altadamon and Eldubha areas in the northern state of Sudan during year 2006. It included 182 girls of age between 13 to 18 years in elementary and secondary school. WORK RESULTS The mean age at menarche fo...

OBJECTIVE We sought to examine whether age at menarche has changed over the past 4 decades by comparing age at menarche by year of diagnosis with type 1 diabetes. RESEARCH DESIGN AND METHODS This work consisted of a cross-sectional study of age at menarche in two cohorts: adolescents (ages 11-24 years, n = 228) and adults (ages 19-55 years, n = 290, enrolled in the Coronary Artery Calcificati...

The hypothesis that the vacation-study-expectancy scholar regime produces most of the monthly rhythm of the age at menarche (AaM) was tested. Studies on monthly menarche incidence (MI) refuted climatic factors as a main factor in this rhythm, and indicated that the main factor of this rhythm is the succession of expectancies of study (Stu-months) or vacation (Vac-months) months within a year. T...

Age at menarche (AAM), time of first menstrual period, is an important developmental milestone in females. Follow-up data from 1,302 adolescent twins and their sisters were used to partition the normal variation in AAM. The proportion of censoring was 14.1%. Both a standard and a survival analysis method were used. The best fitting model from the survival analysis method was an ACE model, where...

BACKGROUND Declining age at menarche has been observed in many countries. In China, a decrease of 4.5 months per decade in the average age at menarche among the majority Han girls has recently been reported. However, the trends in age at menarche among ethnic minority girls over the past 25 years remain unknown. OBJECTIVES To compare the differences in median age at menarche among girls aged ...

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, a...

The purpose of this study was to investigate the secular trend of menarche age within the last 35 years in an immigrant urban city in Turkey-İzmir. We found the mean age at menarche as 13.10±1.18 years for 121,257 women. The reported mean age at menarche showed a decreasing trend over time. For women born before 1963 (≥40 years of age), the mean age at menarche was 13.08±1.21 years. For women b...

OBJECTIVE More than 30 years ago Frisch and Revelle proposed a body weight threshold for the onset of menarche. Based on this hypothesis, a further acceleration of age at menarche can be expected in times of childhood obesity. DESIGN A cross-sectional study of 1840 healthy school girls (Berlin school children's cohort, BSCOC) within the age groups 10-15 years was conducted in 2006-2007. MET...