The study will assess the safety of a sex hormone (levonorgestrel) releasing T-shaped intrauterine contraceptive system in female adolescents under 18 years of age. Approximately 300 generally healthy, post-menarcheal female adolescents with regular menses at the beginning of the study requiring contraception will be enrolled into the study.

Duration of study treatment is approximately 12 months with an option to continue the use of the contraceptive system up to three years if the woman is willing to continue the use after the first 12 months.

The incidence of adverse events over 12 month treatment period will be the main outcome of this study. Also the efficacy (number of pregnancies), discontinuation rate and pharmacokinetics will be evaluated.

Inclusion Criteria:

• The subject has signed and dated the informed consent form (ICF)
• The subject is female, generally healthy, post-menarcheal, nulliparous or parous, requiring contraception, and is under 18 years of age at the Screening visit
• The subject has regular menstrual cycles without hormonal contraceptive use (at regular intervals of 21-35 days)
• In the opinion of the investigator, the subject has general and uterine conditions suitable for the insertion of levonorgestrel intrauterine contraceptive system (LCS12) (uterine sound depth 6-10 cm)
• Has clinically normal safety laboratory results
• The subject has a normal or clinically insignificant cervical smear (i.e. one that does not require further follow up according to Bethesda or a comparable system)
• The subject is willing and able to attend the scheduled study visits and to comply with the study procedures

Exclusion Criteria:

• Known or suspected pregnancy or is lactating
• Vaginal delivery, cesarean delivery, or abortion less than 6 weeks before Visit 1
• History of ectopic pregnancies
• Infected abortion or postpartum endometritis less than 3 months before Visit 1
• Abnormal uterine bleeding of unknown origin
• Any lower genital tract infection (until successfully treated)
• Acute or history of recurrent pelvic inflammatory disease
• Congenital or acquired uterine anomaly