Age at menarche and the menstrual pattern of secondary school adolescents in northwest Ethiopia

Menarche is the onset of menstruation and it is one of the most significant milestones in a woman's life. The mean age at menarche varies from population to population and is known to be a sensitive indicator of various characteristics of population including nutritional status, geographical location, environmental conditions and magnitude of socioeconomic inequalities in a society [1–3]. Studies suggested that menarche tends to appear earlier in life as the sanitary, nutritional and economic conditions of a society improve [4, 5]. For most females, it occurs between the age of 10 and 16 years; however, it shows a remarkable range of variation[3]. The normal range for ovulatory cycles is between 21 and 35 days. While most periods last from three to five days, duration of menstrual flow normally ranges from two to seven days. For the first few years after menarche, irregular and longer cycles are common [3, 6, 7].

Knowledge of the length and variation of the menstrual cycle is necessary for patient education and for identifying deviations from normal to guide clinical evaluation[7]. Among the gynaecological problems, menstrual problems are said to be the major ones especially among adolescent females [6, 7]. These disorders are often the source of anxiety for female adolescents and their families at large. The common menstrual disorders for female adolescents are amenorrhea, abnormal/excessive uterine bleeding, dysmenorrhea, and premenstrual syndrome [6, 7].

Population studies on normal and dysfunctional characteristics of menstrual cycles are scarce in Ethiopia. The purpose of this paper is therefore, to determine the age at menarche and patterns of menstruation among secondary school girls, and to identify the magnitude of common menstrual disorders.

There were no statistically significant differences (t = 2.2, p-value > 0.06) between mean menarcheal ages of Koladiba (15.7 ± 1) and that of Dabat (15.9 ± 1) female students who took part in the study (Table 3).

Out of the total study population, 117(20.7%) adolescents had a menstrual cycle length shorter than 21 days, 51(9%) longer than 35 days and 70% had a cycle length between 21 and 35 days. There is a statistically significant difference on cycle length among the subjects living in Dabat and Koladiba district (X² = 10.9, p-value < 0.03). The difference between the length of the cycle by place of residence (urban, rural) is also significant (X² = 9.6, p-value < 0.05).

The duration of menstruation was taken to the nearest whole day, as information about the hour at which menstruation began and ceased could not be obtained. The mean duration of flow was 4 ± 1.3 days with a range of 2-7 days. The difference between these mean values was not statistically significant by district, residence or age of menarche.

Only 37.6% use sanitary pad and in these group the average number of pads used per day was 3 ± 1.84 (range 1-12). The rest 353(62.4%) use pieces of clothes as sanitary goggle and it was impossible to determine the size and number of pieces used. The proportion of girls who used sanitary pads was higher in urban areas (57.9%) as compared to rural girls (42.1%) (P value < 0.01). Average number of pads used per day was also found more in urban girls (3.4 ± 2 pads per day) than rural girls (2.7 ± 1.5) which is statistically significant with p-value < 0.001.

Premenstrual symptoms were present in 426 girls (75.4%). The most common symptom was abdominal cramp, which was experienced by 330 (76.2%) of those with PMS. There was statistically significant association between presence of premenstrual symptoms and district of residence and regularity of the cycle (Table 4). PMS was not significantly associated with age at menarche, duration of menses, cycle length (Table 4). A significantly higher proportion of female adolescents who had premenstrual symptoms also suffered from dysmenorrhoea (82.4%) compared to adolescents who had no premenstrual symptoms (40.3%).

From the total study subjects, 564 (92.1%) reported they had got information about menarche from someone. The leading sources of menarcheal information were mothers (39.7%), followed by friends (26.6%) and teachers (21.8%).

Menarche is an important event in a woman's life showing (directly or indirectly) many socioeconomic, environmental, nutritional and geographical differences in societies [4, 12–14]. Age of menarche was found to be delayed by both probit analysis (14.8 year) and recall method (15.8 year) in this study which is even higher than similar study in the same region by Haile and Roth two decades ago[15]. Even higher than a study done more than three decades ago in Addis Ababa, Ethiopia, which was 13.6 ± 1.5 years [16]. Another study conducted in Addis Ababa reported a lesser mean age of menarche as 13.72 ± 1.31 years[17]. The probit analysis also showed that the menarcheal age in our study was also found higher than many African countries [Nigeria 13.19 ± 1.32 years for urban and 14.22 years for rural areas[18], Sudan = 13.85[19], Morocco = 13.66[11], Mozambique 13.9 ± 1.29[20]. As age and age at menarche were asked as age in whole years, the data about age and age at menarche may not be very precise.

There was no significant difference in the mean age at menarche of the two areas of different altitudes in our study i.e. Dabat (15.9 ± 1) versus Koladiba (15.7 ± 1) p > 0.06 which disagree with a study in Peru[21] and India [22] which showed an increase in the mean age of menarche with altitude. The reason may be the small sample size of the study or Dabat is not situated at high enough attitude to significantly affect the age at menarche.

The mean age of menarche for rural female adolescents was significantly higher than for urban ones, which is in agreement with the result found in Nigeria[18] and Morocco[11]. This can be explained by the better socioeconomic status for urban girls than rural ones and the lack of fat for rural girls due to malnutrition. Besides, rural girls travel long distances to school every day which may partially put them to stress and delay their menarche.

About 30% of the study subjects had experienced abnormal menstrual cycle length (<21 days or >35 days) which is a common phenomenon in the first two years after menarche[6]. This is because anovolation is common at this time [6, 7]. Other causes of menstrual irregularity like endocrine disorders, tumours and acquired disorders like stress, strenuous exercise and cigarette smoking are potential topics for further research.

In this study dysmenorrhea (pain during menstruation) was reported by 72% of the study subjects of which about 28.5% were having moderate to severe dysmenorrhea. A study done among Malaysian school girls [23] showed a similar result (67.7%) with ours. In our study, dysmenorrhea was more common among those who had irregular cycles, longer duration of flow, rural residents, from Koladiba district and those who had premenstrual syndrome. In the study done in the US by Banikarim et al, dysmenorrhea was the leading cause of short-term school absenteeism [24] which is similar to our study in which about 48.8% of those suffering from dysmenorrhea had reported to be absent from school merely due to the pain. This again agrees well with many studies which reported a 34-50% of school absenteeism due to dysmenorrhea [23, 25–27].

About 75.4% percent of adolescent female students had at least one symptom of PMS in the last 6 month. It is similar to a study done in Malaysia (75%) [23] but lower than the figure reported in a study done among Jimma University students[28] where 99.6% of students had at least one premenstrual symptom in the last 12 months. Since PMS is a leading cause of school absenteeism and unnecessary suffering, it is important that girls are given counselling and offered proper guidance.

In this study 67.4% of the girls reported that they use homemade sanitary pads which is slightly higher than the finding shown in a study done in Addis Ababa(47.8) [17]. Attempts to measure menstrual blood loss on the basis of number of pads or tampons used per day or frequency of pad changes was not successful because of variations in individual fastidiousness, type and brands of sanitation product used and individual estimation of volume of flow.

Menarche may remain a traumatic event for a female adolescent unless she was prepared for it[29]. Mothers were found as potential sources of information in urban girls where as teachers for rural girls. This agrees with studies done in India [30] and Malaysia [23]. The difference in the source of information between rural and urban girls may be due to poor knowledge of rural mothers about menstruation which makes them refrain from advising their daughters about menstruation and related reproductive health issues.

Compared to similar studies carried out in other African countries, menarcheal age was found to be delayed in our study. Age at menarche varies by residence i.e. later among rural subjects of the study than urban ones. Dysmenorrhea was a common problem in school adolescents with significant short-term school absenteeism however, there still exists less practice of medical consultation for the problem though there is high prevalence of dysmenorrhea. Mothers and teachers were potential sources of information on menarche for school girls in urban and rural girls respectively.