Contraception

Inclusion Criteria

-The subject has signed and dated the Informed Consent Form (ICF).
-The subject is healthy when requesting contraception.
-The subject is between 18 - 29 years of age (inclusive) at the time of signing the ICF.
-The subject has normal or clinically insignificant cervical smear for oncocytology (i.e. Pap test) not requiring further follow up (a cervical smear has to be taken at the Screening Visit [Visit 1] or a normal result has to have been documented within the previous 6 months).
-The subject has a history of regular (i.e., endogenous cyclicity without hormonal contraceptive use) cyclic menstrual periods (length of cycle 21 - 35 days), as confirmed by the subject.
-The subject is willing and able to attend the scheduled study visits and to comply with the study procedures.

Exclusion Criteria

-Pregnancy or current lactation (less than 6 weeks postpartum or since abortion before the Screening Visit)
-Infected abortion or postpartum endometritis within 3 months prior to the Screening Visit.
-Chronic, daily use of drugs that may increase serum potassium levels.
-Undiagnosed abnormal genital bleeding.
-Acute cervicitis or vaginitis (until successfully treated).
-Lower urinary tract infection (until successfully treated).
- Acute or recurrent pelvic inflammatory disease or conditions associated with increased risk for pelvic infections.
-Congenital or acquired uterine anomaly including fibroids, in the opinion of the investigator, which would interfere with insertion and/or retention of the intrauterine system (i.e., if they distort the uterine cavity).
-Cervical neoplasia, uterine or cervical malignancy, or sex hormone-dependent tumors.
-History of migraine, focal migraine with asymmetrical visual loss or other symptoms indicating transient cerebral ischemia.