<p>Latar Belakang: Pola siklus menstruasi disebut normal apabila tidak kurang dari 21 hari serta tidak melebihi 35 hari. Tujuan: Diketahuinya hubungan antara indeks massa tubuh dan usia menarche terhadap panjangnya siklus menstruasi pada siswi SMA di Pontianak. Metode: Penelitian analitik observasional cross sectional. Variabel bebas penelitian adalah indeks massa tubuh dan usia menarche, variabel terikat adalah panjangnya siklus menstruasi. Total sampel penelitian 40 orang. Hasil: Terdapat hubungan antara indeks massa tubuh dan panjangnya siklus menstruasi (uji Fisher’s Exact p = 0,02). Tidak terdapat hubungan antara usia menarche dan panjangnya siklus menstruasi (uji Chi-Square p = 0,305). Simpulan: Indeks massa tubuh berhubungan dengan panjangnya siklus menstruasi siswi.</p><p>Background: Menstrual cycle pattern is normal if not less than 21 days and not exceed 35 days. Objective: To evaluate the relationship between body mass index and age of menarche on the menstrual cycle among female senior high school students in Pontianak. Method: Observational analytic study with cross sectional design. The independent variables were body mass index and age of menarche, the dependent variable was menstrual cycle. Total sample were 40 students. Results: There is a relation between body mass index and the menstrual cycle (Fisher’s Exact test p = 0,02). No relation between age of menarche and the menstrual cycle (Chi-Square test p = 0,305). Conclusion: Body mass index has a relation toward the menstrual cycle among female senior high school students in Pontianak.</p>

Latar Belakang: Pola siklus menstruasi disebut normal apabila tidak kurang dari 21 hari serta tidak melebihi 35 hari. Tujuan: Diketahuinya hubungan antara indeks massa tubuh dan usia menarche terhadap panjangnya siklus menstruasi pada siswi SMA di Pontianak. Metode: Penelitian analitik observasional cross-sectional. Variabel bebas penelitian adalah indeks massa tubuh dan usia menarche, variabel terikat adalah panjangnya siklus menstruasi. Total sampel penelitian 40 orang. Hasil: Terdapat hubungan antara indeks massa tubuh dan panjangnya siklus menstruasi (uji Fisher’s Exactp = 0,02). Tidak terdapat hubungan antara usia menarche dan panjangnya siklus menstruasi (uji Chi-Square p = 0,305). Simpulan: Indeks massa tubuh berhubungan dengan panjangnya siklus menstruasi siswi. Background: Menstrual cycle pattern is normal if not less than 21 days and not exceed 35 days. Objective: To evaluate the relationship between bodies mass index and age of menarche on the menstrual cycle among female senior high school students in Pontianak. Method: Observational analytic study with cross-sectional design. The independent variables were body mass index and age of menarche, the dependent variable was menstrual cycle. Total sample were 40 students. Results: There is a relation between body mass index and the menstrual cycle (Fisher’s Exact test p = 0,02). No relation between age of menarche and the menstrual cycle (Chi-Square test p = 0,305). Conclusion: Body mass index has a relation toward the menstrual cycle among female senior high school students in Pontianak.