Search

OBJECTIVES: To assess the contraceptive efficacy, tolerability and acceptability of hormonally impregnated intrauterine systems (IUSs) in comparison to other reversible contraceptive methods. SEARCH STRATEGY: Literature was identified through database searches, reference lists and individuals/organisations working in the field. SELECTION CRITERIA: All randomised controlled trials comparing IUSs with other forms of reversible contraceptives and reporting on pre-determined outcomes in women of reproductive years. The primary outcomes were pregnancy due to method/user failure and continuation rate. DATA COLLECTION AND ANALYSIS: The quality assessment of studies and data extraction were completed independently by two blinded reviewers. A quality checklist was designed to identify general methodological and contraceptive specific factors which could bias results. Events per women months and single decrement life table rates were extracted where possible for pregnancy, continuation, adverse events and reasons for discontinuation. Events per total number of women at follow up were collected for hormonal side effects and menstrual disturbance. When appropriate, data were pooled at the same points of follow up to calculate rate ratios in order to determine the relative effectiveness of one method compared to another. For the single decrement life table rates, the rate differences were pooled to determine the absolute difference in effectiveness of one method compared to another. Interventions were only combined if the contraceptive methods were similar. Non-hormonal IUDs were divided into three categories for the purpose of comparison with IUSs: IUDs >250mm2 (i.e. CuT 380A IUD and CuT 380 Ag IUD), IUDs 250mm2 users. However, women using the LNG-20 IUS were significantly less likely to become pregnant than those using the IUD 250mm2. LNG-20 users were significantly more likely than all the IUD users to discontinue because of hormonal side effects and menstrual disturbance, which on further breakdown of the data was due to amenorrhoea. When the LNG-20 IUS was compared to Norplant-2, the LNG-20 users were significantly more likely to experience amenorrhoea and oligomenorrhoea, but significantly less likely to experience prolonged bleeding and spotting. No other significant differences were observed. Progestasert users were significantly less likely to become pregnant and less likely to continue on the method than non-medicated IUD users after one year, but no significant differences was noted for these two outcomes when Progestasert users were compared to IUD 250mm2 and Norplant-2 users. The LNG-20 IUS was more effective in preventing either intrauterine or extrauterine pregnancies than IUDs