Inclusion Criteria:

• Sexually active women, at risk for pregnancy and not planning to use condoms;
• Women in need for contraception and willing to use an OC for 12 months (13 cycles);
• At least 18 but not older than 50 years of age at the time of screening;
• Body mass index >=17 and <=35;
• Good physical and mental health;
• Willing to give informed consent in writing.

Exclusion Criteria:

• Contraindications for contraceptive steroids
• In accordance with the SmPC/Package Insert of DRSP-EE, additional contraindications related to the antimineralocorticoid activity of drospirenone (conditions that predispose to hyperkalemia):
• Renal insufficiency;
• Hepatic dysfunction;
• Adrenal insufficiency.
• An abnormal cervical smear (i.e.: dysplasia, cervical intraepithelial neoplasia [CIN], SIL, carcinoma in situ, invasive carcinoma) at screening;
• Clinically relevant abnormal laboratory result at screening as judged by the investigator;
• Use of an injectable hormonal method of contraception; within 6 months of an injection with a 3-month duration, within 4 months of an injection with a 2-month duration, within 2 months of an injection with a 1-month duration;
• Before spontaneous menstruation has occurred following a delivery or abortion;
• Breastfeeding or within 2 months after stopping breastfeeding prior to the start of trial medication;
• Present use or use within 2 months prior to the start of the trial medication of the following drugs: phenytoin, barbiturates, primidone, carbamazepine, oxcarbazepine, topiramate, felbamate, rifampicin, nelfinavir, ritonavir, griseofulvin, ketoconazole, sex steroids (other than pre- and posttreatment contraceptive method) and herbal remedies containing Hypericum perforatum (St John's Wort);
• Administration of investigational drugs and/or participation in another clinical trial within 2 months prior to the start of the trial medication or during the trial period.
• Subjects with a diagnosis of the endometrial biopsy such as hyperplasia, atypical hyperplasia, carcinoma or any other abnormality judged clinically relevant by the investigator (This is applicable only for the subjects participating in the endometrial biopsy substudy).