The effect of homozygous sickle cell disease on the age at menarche in Nigerian schoolgirls.

Two thousand two hundred and four schoolgirls from four secondary schools in Enugu, the capital of Anambra State in south-eastern Nigeria, were interviewed and provided information regarding their age, menstrual status and the presence or absence of some common chronic disorders. Sickle cell disease was identified and confirmed by haemoglobin electrophoresis in 1.36% of the students. Average age at menarche, determined by probit analysis, was significantly delayed among subjects with sickle cell disease when compared with normal students (14.5 +/- 1.13 years vs. 13.3 +/- 1.09 years; P less than 0.005). Comparison of the average menarcheal age of the normal subjects in this study with previous reports of studies from southern Nigeria confirms a continuing decline of the average age at menarche at a rate of about four months per decade.