Mulu, Abay(Assistant Professor in Anatomy)Boshe, Mengistu2018-11-292023-11-292018-11-292023-11-292018-11http://etd.aau.edu.et/handle/123456789/14697Background: The onset of menstruation is part of the maturation process. However, variability in age at menarche, menstrual cycle characteristics, factors that affect onset of menstruation and related disorders are common.Knowledge on this variability is necessary for patient education and to guide clinical evaluation. VII Objective:To assess the age at menarche and menstrual cycle patterns among adolescent school girls in GamoGofa zone, Southwest Ethiopia. Methodology:Across-sectional study design was conducted in two towns called Chencha and A/Minch between May–June 2017 in Southwest Ethiopia.Systematic samplingtechnique was used to select 613 school girls from two secondary schools. Data were collected using a self-administered structured questionnaire.Data was entered and cleaned to Epi-data software version 3.1 and exported to SPSS version 22 for analysis. Descriptive data analysis was done first using frequency, percentage, cross tabulation, median and mean. Table and graphs were used for data presentation. Result The ages of the study subjects range between 13 and 19 years with a mean of 16.02 ± 1 year and median of 16.00. The average age at menarche by recall method was 14.17±1 years. The mean age at menarche was 0.5 years younger for urban (13.98 ± 0.9) females compared with rural(14.48 ± 1.2) ones. The mean menarcheal age difference between A/Minch town (13.97 ±1) and Chencha town (14.36 ± 1) school student girls was 0.39 with p-value < 0.001.The menstrual cycles were irregular in 112 (18.3 %) of the subjects. A cycle length between 21 and 35 days was observed in 52.1% of the girls. The mean duration of flow was 3.74 ± 1.2 days with a range of 1-9 days. The overall prevalence of dysmenorrhoea was 75.5% among the participants. Premenstrual symptoms were present in 428 of the females (69.8%). In the adjusted odds ratio, adolescents who were living in urban areas were 2.42 times earlier probability to see menarche as compare to adolescent school girls who living in rural areas(AOR= 2.42, 95% CI: 1.59, 3.69). In the adjusted odds ratio, adolescents who were living in ArbaMinch town were 2.08 times earlier probability to see menarche as compare to adolescent school girls who living in Chencha town (AOR= 2.08, 95% CI: 1.36, 3.18). Conclusion:In this study age of menarche was found to be earlier than the study conducted in the same country with the different region, but higher than in the same region in different population and time in Ethiopia. A significant number of students complain of the abnormal menstrual cycle, dysmenorrhoea and premenstrual symptoms which call for appropriate counseling and management.en-USAge at menarche, menstrualcycle pattern, altitude, Ethiopia.Thesis