Evaluation of the extended regimen versus standard regimen of oral contraceptive in premenstrual and/or menstrual symptoms

INTERVENTION: Subjects will be randomised to receive either 3 mg drospirenone/20 µg ethinyl estradiol in extended regimen (168 days of uninterrupted treatment) or drospirenone 3 mg/ethinyl estradiol 20 µg in standard regimen (6 cycles of 24 days of treatment followed by 4‐day tablet free interval). Subjects will record the scores of symptoms and patterns of bleeding in a daily diary. Questionnaire for Quality of Life (Short WHOQOL) will be applied in visits C1 (after 1 month of treatment), C2 (after 3 months of treatment) and C4 (after 6 months of treatment). CONDITION: Premenstrual symptoms ; Urological and Genital Diseases ; Premenstrual symptoms PRIMARY OUTCOME: Percentage of reduction in the total score of symptoms as recorded in the Daily Symptom Report (DSR‐17) after treatment with 3 mg drospirenone/20 µg ethinyl estradiol in extended regime compared to standard regime. SECONDARY OUTCOME: 1. Bleeding pattern ; 2. Questionnaire for Quality of Life (Short WHOQOL) ‐ Portuguese version, applied in visits C1, C3 and C4; 3. Significant change in laboratory tests and clinical parameters INCLUSION CRITERIA: 1. Females of child bearing age (18 ‐ 39 years) 2. At least three regular menstrual cycles lasting between 25 and 35 days, with 3 ‐ 7 days of bleeding, without occurrence of intermenstrual bleeding and without amenorrhoea 3. Willingness to contraception and to meet the requirements of the study 4. Available to receive telephone calls 5. Competence to consent to participate in the study and sign the ICF 6. Education of at least four years or good ability to understand spoken and written information as testified by investigator 7. Complaint of at least one physical symptom and one emotional symptom in the premenstrual and/or menstrual period with intensity greater than or equal to two points according to scores of "Daily Symptom Report (DSR‐17)" recorded by patient in the screening phase