the association between menarche age and birth weight, mother and older sister's age of menarche

Background: age of menarche is a sign of the beginning of the ability to reproduce and is usually a turning point for the development and maturity and puberty. regulatory factors in the onset of menarche age are not well understood, but in developed countries, it is thought that about half of the variations in the onset age of menarche is associated with genetic factors. objectives: to determine the association between menarche age, birth weight and the mother and older sister’s age of menarche; the subjects of this study were shirazi female primary, middle and high schools students in 2014 - 2015. methods: this is a cross-sectional study, which was done on 2000 girls aged 9 - 18 years. in the first stage, sampling of schools in 4 regions was randomly assigned to clusters. then, the students in each school were selected purposively. the questionnaires filled in by the participants contained demographic items, menarche age, and birth weight. data were analyzed through spss (version16), using chi-square test and anova. results: the majority of the subjects (n: 1294, 64.7%) had normal menarche age (11 - 14 years old). there was no relationship between menarche age and birth weight (p: 0.67). however, it was significantly associated with the students’ mother and older sister’s age of menarche (p: 0.001). conclusions: according to the findings, menarche age was within the normal range (11 - 14 years) in the majority of the subjects. there was a significant positive association between menarche age in both mothers and girls. in other words; girls reach menarche age earlier than their mothers. thus, and mother and older sister’s menarche age can be a proper criterion to predictit in girls.