Menarchal age in Nigerian schoolgirls: its relationship to their height, weight and menstrual profile.

Interviews with 119 students in a girls' residential secondary school in Ondo, Nigeria, revealed that 105 of them had menstruated, their mean age at menarche being 13.85 years, their mean height 156.8 cm and their mean weight 51.13 kg. The duration of menstrual bleeding was 4.43 days, the heaviest occurring at 1.82 days. Dysmenorrhea was reported by 32%. There was no correlation between the weight/height ratio and the mean age of the study group who were menstruating and the 14 students who were not. However, the difference in mean weight and height of those who had and had not attained menarche was significant. It is suggested that certain levels of weight and height are critical to achievement of spontaneous menstruation.