The factors affecting the relation between the menarcheal age of mother and daughter.

BACKGROUND: Menarche is one of the most important biologic signals in the life of a woman. Menarche is a biological variable which has a significant genotypic component in girls. In recent years, many studies reporting the earlier onset of menarche owing to the improvement of socio-economic conditions have been published.
DESIGN: We asked some questions about menarche to 1017 female students studying in the high schools of Manisa region in order to determine the menarcheal age and the correlation of menarcheal age between the mothers and daughters in our region.
RESULTS: The mean age at menarche for the girls was 12.82+/-1.07 years and for the mothers was 13.6+/-1.39 years. The mean menarcheal age of the mothers was higher than the mean menarcheal age of the girls (P<0.001). This difference persisted independent of the socio-economic status, nutritional state and physical activity of the girls. There was a significant correlation between the menarcheal age of the girls and their mothers (r=0.262, P<0.001). This correlation existed in all the girls with different socio-economic status, nutritional state and physical activity. However, this correlation disappeared in girls with body mass index (BMI)>25 (r=0.04, P=0.813). In girls with BMI<25, there was a correlation between the menarcheal age of the girls and mothers (r=0.282, P<0.001).
CONCLUSION: These results suggest that the menarche occurs earlier in the daughters than their mothers. The correlation between the menarcheal age of the girls and their mothers persists under all circumstances except in obesity. The mother's menarcheal age is a good predictor of the daughter's menarcheal age in non-obese girls and the BMI is an important factor.