¿Cuál es el impacto de los métodos anticonceptivos y las combinaciones de éstos en la prevalencia de uso de métodos anticonceptivos, la necesidad insatisfecha de planificación familiar y los embarazos no deseados y no planificados? Una revisión panorámica de revisiones sistemáticas.

WHAT DO WE WANT TO KNOW?: In many low-and middle-income countries, there is high maternal, infant and child mortality due in part to low contraceptive use and high unmet need for family planning. The aim of this overview of systematic reviews is to synthesise the findings of systematic reviews conducted in this area to assess the impact of various contraceptive methods and mixes of contraceptive methods on contraceptive prevalence, unwanted and unintended pregnancies, and unmet need (a desire to limit the number of children but not currently using any contraception) for family planning in developing countries/regions. REVIEW OBJECTIVES: The specific objectives of the proposed overview of systematic reviews are: To assess the impact of various contraceptive methods and mixes of contraceptive methods on contraceptive prevalence in developing countries/regions. To assess the impact of various contraceptive methods and mixes of contraceptive methods on unwanted and unintended pregnancies in developing countries/regions. To assess the impact of various contraceptive methods and mixes of contraceptive methods on unmet need for family planning in developing countries/regions. WHAT DID WE FIND?: This review examined a range of contraceptives methods, including modern and traditional methods. However, systematic reviews included in the review of reviews did not address all the objectives listed above. This review mainly focused on interventions relating to female sterilisation using clips and rings, and these were found to be equally efficacious in preventing pregnancy. There is moderate quality evidence to favour second generation oral pill (monophasic norgestrel 0.3mg/EE 30mcg) over first (monophasic norethindrone acetate 1.5mg/EEmcg) in preventing pregnancy (RR=0.12, 95%CI 0.02, 0.99). High quality evidence to support the programmatic use of TCU380A intrauterine device over the Multiload Cu375 device (Rate difference=0.75, 95%CI 0.13, 0.37 at 1 year). Low quality evidence that two-monthly injections of NET-EN/E2V 50mg and three-monthly injections of DMPA/E2c 5mg (Peto OR = 1.95, 95% CI 0.53, 7.20) did not show any difference in pregnancy prevention. Low-quality evidence that the two implants Implanon and Norplant reduce the risk of pregnancy. Moderate-quality evidence that mid-dose mifepristone (25-50mg) is more effective than low-dose mifepristone (<25mg) for emergency contraception (RR= 0.66, 95% CI 0.47, 0.91). Moderate-quality evidence that there is no difference between spermicides in preventing pregnancy. It was not possible to present evidence on the included outcomes for male/female condoms, diaphragms, vasectomy, skin patches or vaginal rings. WHAT ARE THE IMPLICATIONS?: More systematic reviews are needed to study outcomes such as contraceptive prevalence and unmet need for contraception. With regard to female sterilisation, considerations of cost, infrastructure issues and risk and severity of side effects might inform programme decisions. For oral contraceptives the choice of preparation to be included in programming might be more usefully informed by availability in countries and cost. HOW DID WE GET THESE RESULTS?: Twenty two systematic reviews were included in this overview of systematic reviews. We searched Bioline international, The Cochrane Library, Latin American and Caribbean Health Sciences Literature - LILACS, Popline, PubMed, Turning Research Into Practice, World Health Organisation Reproductive Health Library and Zetoc. Searches were carried out during October-December 2010. Twenty-two systematic reviews included in this overview. Data were extracted and synthesised narratively. A Measurement Tool to Assess Systematic Reviews, AMSTAR, was used to evaluate the quality of the included systematic reviews, and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used to evaluate the quality of the body of evidence for each comparison.