The age of menarche in Nigerian urban school girls.

In March and April 1978, a sample of 1365 girls from three secondary schools within and near Enugu (capital of Anambra State of Nigeria) were interviewed regarding date of birth and menstrual status. Using probit analysis, the mean age at menarche was 13.54 +/- 0.07 years, implying, when compared with earlier studies, a rate of decline in the average menarcheal age of about four months per decade. Significant differences were observed in the menarcheal ages of the girls with respect to their geographical residence and the occupation of their fathers. The results obtained in the study are similar to those reported by Oduntan et al. (1976) for south-western Nigeria, and they lend support to the proposition that improvements in nutrition and the elimination of infectious diseases (characteristic associated with socioeconomic development) tend to reduce the average menarcheal age.