Age, seasons and influence of body mass index on menarche among secondary school girls in Port Harcourt, Nigeria

Menarche is a significant marker of maturity and puberty in girls, it transition influenced by different biophysical factors. This study was carried out to determine the age, seasons influence body mass index (BMI) on menarche. A total 450 girls’ between ages 10 19 years participated study. Age at menarche obtained via recall quo cross sectional method. Parameters measured were; standing height (SH), weight (Wt) BMI. 373 (82.9%) girls had their early adolescence while 77 (17.1%) mid adolescence. Mean age 13.17± 1.48 years. The average value for BMI 20.35 ± 3.77 kg/m2, SH 161.09 6.16 cm, Wt 52.53 9.21kg. Overweight were observed attain earlier, followed those whose mean normal range .Subjects underweight category higher high months August, July January. occurs among secondary school Port Harcourt other factors, associated with stress are important onset biological event.