Age at menarche and associated nutritional status variables in Karimui and Daribi census divisions of Simbu Province.

Age at menarche was estimated from data on 310 girls and young women living in Karimui and Daribi census divisions of Simbu Province in 1987. The area has high malnutrition rates among children under five years of age and short adult female stature suggesting that onset of menses should be late. However, other work has shown young ages at the birth of first children and high overall fertility rates among women. The prediction of age at menarche from adult female height is not valid for this population; the actual age at which 50% of girls had commenced menstruating is approximately one and a half years earlier, at 15.8 years, than the predicted age. The nutritional status variables investigated and found to be associated with the age at menarche are height, weight and triceps skinfold thickness. At any given age girls whose nutritional status was better, particularly in terms of weight, were more likely to have commenced menstruation. Menarche appears to be followed closely by onset of reproductive function, with the age at the birth of first children estimated at 17.2 years. A consequence of early entry into reproduction, particularly for girls in areas where undernutrition is common, is a period of considerable nutritional stress during adolescence. Intervention programs should consider this and target these groups for additional health, family planning and nutritional advice.