title: Comparative performance of a combined injectable contraceptive (50 mg norethisterone enanthate plus 5mg estradiol valerate) and a combined oral contraceptive (0.15 mg levonorgestrel plus 0.03 mg ethinyl estradiol) in adolescents.
abstract: OBJECTIVE
  To compare in a regular non-clinical trial experience the efficacy, acceptability, and continuation rates of an injectable contraceptive containing 50 mg norethisterone enanthate plus 5mg estradiol valerate (IC) and an oral contraceptive containing 0.15 mg levonorgestrel plus 0.03 mg ethinyl estradiol (OC), among adolescent users.
  
  
  METHODS
  A total of 251 adolescents ages 14-19 were followed during 12 months. The IC group (124 subjects) was studied for 1044 cycles and the OC group (127 subjects) was studied for 1368 cycles. The users were not assigned in a random selection. Information was collected from clinical records. Groups were compared using Pearson chi-square, odds ratio (95% confidence interval), t-test, and proportion difference test.
  
  
  RESULTS
  The IC group had significant differences in baseline social risk, confidence, psychiatric problems, consumption of alcohol, and number of sexual partners. At 12 months, the IC group showed significant decrease in weight and increase in hypermenorrhea. In the OC group, dysmenorrhea decreased, and hypomenorrhea and regular cycles were significantly more frequent. One pregnancy occurred in the OC group (Pearl Index: 0.88). Final continuation rates at 12 months were 41.9% and 37.8% for IC and OC, respectively.
  
  
  CONCLUSIONS
  The monthly injectable is a recommended contraceptive option for adolescents, especially for those facing psychosocial risk factors.
authors.affiliation: Center for Adolescent Reproductive Medicine, Faculty of Medicine, University of Chile, Santiago, Chile. rmolina@med.uchile.cl
authors.forename: Ramiro C
authors.initials: RC
authors.lastname: Molina
authors.forename: Jorge Z
authors.initials: JZ
authors.lastname: Sandoval
authors.forename: Adela V
authors.initials: AV
authors.lastname: Montero
authors.forename: Pamela G
authors.initials: PG
authors.lastname: Oyarzún
authors.forename: Temístocles G
authors.initials: TG
authors.lastname: Molina
authors.forename: Electra A
authors.initials: EA
authors.lastname: González
mesh_terms: D000293:Adolescent; D000554:Ambulatory Care Facilities; D003277:Contraceptives, Oral, Combined / Q000008:administration & dosage* / Q000009:adverse effects; D004334:Drug Administration Schedule; D004338:Drug Combinations; D004958:Estradiol / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D004997:Ethinyl Estradiol / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D016912:Levonorgestrel / Q000008:administration & dosage / Q000009:adverse effects; D055118:Medication Adherence; D009640:Norethindrone / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D017060:Patient Satisfaction; D011446:Prospective Studies; D055815:Young Adult
chemical_list: D003277:Contraceptives, Oral, Combined; D004338:Drug Combinations; D004997:Ethinyl Estradiol; D004958:Estradiol; D016912:Levonorgestrel; C024319:norethindrone enanthate; D009640:Norethindrone