To evaluate the contraceptive efficacy of an oral contraceptive containing a combination of LNG 90 mg/EE 20 mg in a continuous-use regimen and to evaluate the safety compared to LNG 100 mg/EE 20 mg for 21 days followed by a 7-day hormone-free interval in a cyclic regimen.

Inclusion Criteria:

• Healthy women aged 18 to 49 years who are willing to rely upon a combination birth control pill as their only method of contraception.
• Women must be sexually active and at risk for becoming pregnant.
• Women must have had regular (21- to 35- day) menstrual cycles for the 3-month period preceding study visit 1.

Exclusion Criteria:

• High blood pressure
• Age greater then 34 and smoking more than 15 cigarettes per day.
• Depression requiring hospitalization or associated with suicidal ideation within the last 3 years.