• Safety assessment at 6, 12, 18 and 24 months, including adverse events, physical examination and laboratory parameters
  
• Relapse rate at 6, 12, 18 and 24 months,
  
• EDSS progression at 12 and 24 months,
  
• MS functional composite score at 12 and 24 months,
  

• Number and volume of new gad-enhancing lesions at 12 and 24 months
  
• Number of new T1 and T2 lesions at 12 and 24 months
  
• Brain volume changes at 12 and 24 months
  
• Neuropsychological examination at 0, 12, 24 months
  
• Hamilton scale for depression score at 0, 12, 24 months
  
• MS Quality of Life scale score(MSQOL54)at 0, 12, 24 months
  
• Fatigue Severity Scale score at 0, 12, 24 months
  

Phase 2, randomised, single blind, three arms study.

Follow-up of 24 months.

The study will include relapsing-remitting multiple sclerosis female patients.

Patients will be equally randomised into three groups: 1) patients treated with IFN-beta 1a (44 mcg for three times a week), 2) patients treated with IFN-beta 1a and lower-dose estroprogestins (desogestrel 150 mcg, etinilestradiol 20 mcg), 3) patients treated with IFN-beta 1a and higher-dose estroprogestins (desogestrel 25 mcg, etinilestradiol 40 mcg).

Safety and tolerability of the treatment will be evaluated using neurological examination and MRI analysis.

A complete neurological examination (with EDSS) will be performed at month 0, 6, 12, 18 and 24.

MRI examination will be assessed at baseline and at month 12 and 24. In the same day of MRI examination we'll collect blood samples for hormonal analysis (we'll measure sex hormones in the follicular and in the luteal phase of a single menstrual cycle).

During the follow-up patients will be evaluated also with: MS-Functional Composite at month 0, 6, 12, 18, 24; neuropsychological evaluation at month 0, 12, 24; Fatigue Severity Scale at month 0, 12, 24; Hamilton Depression Scale at month 0, 12, 24; Quality of Life scale (MSQOL54) at month 0, 12, 24.