Abstract:
The menarchial age of 859 secondary school
girls consisting of 508 from urban and 351
from rural area of Rivers State, Nigeria were
determined, using questionnaires and
interview method. Data collation revealed
that 69.2% (243) of the rural population were
menstruating, while 70.1% (356) of the
urban population were menstruating. Mean
ages of menarche were 13.19±1.32 years and
14.22±1.47 years for urban and rural areas
respectively .A statistically significant lower
mean menarchial age was observed in urban
area girls, compared to their rural
counterparts. Girls from families of high
socio-economic class has significantly lower
mean menarchial age in both urban and
rural area. The mean age of menarche was
significantly higher in girls involved in
vigorous sporting activity in rural areas
compared to their non-sporting
counterparts. Urban school girls attain
menarche earlier than those in rural area.
High socio-economic class and vigorous
sporting activity can be predisposing factors
to low and high age of menarche
respectively. There is need for redefinition
of high socio-economic class in Nigeria.
Key Words: Menarchial age, School Girls,
Urban, Rural, Sports, Socio-economic class
Introduction
Menarche is the onset of menstruation. It is
one of the major events within the complex
changes of puberty in girls. Menarche is
believed to be influenced by many factors
including socio-economic class1,2 and
sports.3 Other factors attributed to influence
menarchial age includes rate of physical
growth. It has been observed that girls with
faster physical growth and that were
relatively overweight had faster onset of
menarche.4 Genetic factors have been
suggested to influence menarchial age. HLA
linked genes have been noted to play
important role in determining the age of
menarche.5 However there is no significant
association between the age of menarche
and genetic markers such as ABO blood
group, Rhesus factor, haptoglobulins,
esterase D and phosphoglucomutase.6
Information on the age of menarche is well
documented in Nigeria, Europe and
American girls. But most of the information
in Nigeria was focused on the urban areas of
northern and western Nigeria. There is still
paucity of information on the menarchial
age of Nigerian girls in rural areas,
especially Rivers state, the eastern region of
Nigeria where the quality of life depends
much on the earning power of the citizens.
This study is designed to bridge this gap in
knowledge.
Materials and Methods
Study-Area:
By simple random sampling method, four
secondary schools were selected. Two were
from the urban area (Portharcourt), and
other two from rural area (Etche). The two
schools selected for each group consisted of
one co-education school and another girls-
only school respectively.
Subjects
This included all students from junior
secondary I to senior secondary II of the
selected schools, since the senior secondary
III girls had graduated out as at the time of
the study.
Method of data collation::
Using the retrospective method, about 900
questionnaires were distributed, according
to the population proportion of the four
schools. Of this, 41 were not properly
answered, so we had 508 and 351 properly
answered questionnaires from urban and
rural schools respectively. The questionnaire
was verbally interpreted in simple language
and properly explained to avoid any form of
misunderstanding and to facilitate accurate
response by the subjects. The questionnaires
were retrieved immediately after
completion to minimise interpersonal
communication amongst the subjects and to
prevent the influence of peers on individual
responses.
Ethical consideration::
The authorities of the secondary schools and
the girls concerned were informed and