This is an open-label, multi-centre, comparative study in young, healthy, female volunteers of reproductive age.

Primary objective:

- To investigate the effect of 2 dosages of estetrol combined with P1 or P2, on vaginal bleeding patterns (cycle control), in comparison with a combined oral contraceptive containing estradiol valerate and dienogest

Secondary objectives:

• To investigate ovulation inhibition
• To investigate the effect on SHBG
• To assess pregnancy rate
• To evaluate subject satisfaction, dysmenorrhoea, acne, and body weight
• To investigate return of menstruation after treatment
• To evaluate general safety and acceptability

Inclusion Criteria:

• Women willing to use a Combined Oral Contraceptive for 6 subsequent cycles
• Good physical and mental health
• Regular menstrual cycle (24-35 days) prior to screening
• Body mass index between (≥) 18 and (≤) 30 kg/m2

Exclusion Criteria:

• Previous use of any hormonal contraceptive method during the last 3 months prior to randomisation (only applicable for women who are not using a hormonal contraceptive method at the time of screening)
• Previous use of progestogen-only contraceptive methods during the last 3 months or during the last 6 months for depot progestogen preparations or an injectable hormonal method of contraception
• Use of phytoestrogens
• No spontaneous menstruation has occurred following a delivery or abortion
• Breastfeeding or within 2 months after stopping breastfeeding prior to the start of study medication and no spontaneous return of menstruation
• Status post-partum or post-abortion within a period of 2 months before screening
• Pregnancy during accurate hormonal contraceptive use in the past
• Intention to become pregnant during the study
• An abnormal cervical smear within one year before study start
• Untreated Chlamydia infection
• Known or suspected breast cancer or a history of breast cancer
• A history of (within 12 months) alcohol or drug abuse
• Any clinically relevant abnormality
• Contraindications for the contraceptive steroids used in the clinical trial
• Use of antihypertensive drugs or use of medications interacting with the contraceptive steroids used in the clinical trial
• Administration of any other investigational drug within 2 months prior to screening