Menstrual dysfunction in Nigerian athletes.

Menstrual function was assessed in 475 Nigerian athletes in different sports and 606 non-athletes. In general, irregular menstrual cycles and oligomenorrhoea or secondary amenorrhoea (O/A) were more common in the athletes (26% and 21%, respectively) than in the non-athletes (18% and 8%, respectively). Menstruation was more regular and normal in the non-athletes (50%) than in the athletes (22%). It was noted that menstrual dysfunction in the athletes was associated with significantly low body fat, body weight, relative weight for height, and the stress of sports activity. In the groups of athletes the ball game players (35%) and distance runners (51%) most commonly experienced O/A, whereas the incidence of dysmenorrhoea and menorrhagia was most prevalent in the swimmers (37%), and sprinters (42%). Menstrual disturbances were relatively more common in athletes who began training before the menarche (43%).