What is the impact of contraceptive methods and mixes of contraceptive methods on contraceptive prevalence, unmet need for family planning, and unwanted and unintended pregnancies?

An overview of systematic reviews

Abstract

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 (want to limit number of children but not using any contraception) for family planning in developing countries/regions.

There were 23 systematic reviews included in this Overview of Reviews. The overview examined a range of contraceptive methods, including modern (terminal and spacing) and traditional methods (methods of family planning generally such as withdrawal and periodic abstinence which do not require contraceptive substances or devices and also do not require clinical procedures). However, these systematic reviews did not address all the objectives of the Overview. Evidence from systematic reviews is lacking about the acceptability of contraceptive methods, and their impact on prevalence and on unmet needs for family planning. The relative effectiveness of a variety of contraceptive methods to prevent pregnancy in developing countries is generally low quality. There is some high quality evidence comparing different derivatives of same contraceptive methods, although this is more often evidence of efficacy than evidence of effectiveness. The results of the review are summarised below according to the objectives.

Objective 1: To assess the impact of various contraceptive methods and mixes of contraceptive methods on contraceptive prevalence in developing countries/regions.
There was no systematic review on the impact of contraceptive methods and mixes of methods on contraceptive prevalence in developing countries.

Objective 2: To assess the impact of various contraceptive methods and mixes of contraceptive methods on unwanted and unintended pregnancies in developing countries/regions.

The body of evidence for the relative efficacy or effectiveness of a variety of contraceptive methods to prevent pregnancy in developing countries was generally rated as low or moderate. There was however a number of comparisons (between different derivatives of same contraceptive methods) for which the evidence was rated as high or moderate quality. Evidence from systematic reviews is lacking about the acceptability of contraceptive methods, and their impact on prevalence and on unmet needs for family planning. The relative effectiveness of a variety of contraceptive methods to prevent pregnancy in developing countries is generally low quality. There is some high quality evidence comparing different derivatives of same contraceptive methods, although this is more often evidence of efficacy than evidence of effectiveness.

Objective 3: To assess the impact of various contraceptive methods and mixes of contraceptive methods on unmet need for family planning in developing countries/regions.
There was no systematic review on the impact of contraceptive methods and mixes of methods on unmet need for family planning in developing countries.

Limitations and conclusions:
This Overview of Reviews could not identify any systematic reviews that could answer all the questions set out in the protocol, particularly those related to outcomes such as contraceptive prevalence and unmet need for contraception. This indicates lack of evidence either in the form of systematic reviews or in primary research. Thus, this Overview of Reviews points out the need to either undertake Systematic Reviews or RCTs (where these are possible to perform) or non-RCT/observational studies (where RCTs are not possible to perform). The Overview of Reviews, however, did provide an opportunity to compare effectiveness of various contraceptive methods on the outcome measures such as pregnancy and continuation. However much of the available evidence in this area is based on a limited number of poorly conducted studies comparing different formulations of the same type of contraceptive; there is a lack of evidence from well designed studies comparing different types of contraceptives in developing country settings across a wider range of outcomes (e.g. to include birth spacing and unmet need for family planning). It was not possible to present evidence on the included outcomes for a number of types of contraception: male condoms, female condoms, diaphragms, vasectomy, skin patches and vaginal rings. The evidence examining traditional methods was particularly weak.

There is a protocol for this systematic review

Citation

Mackenzie, H.; Drahota, A.; Pallikadavath, S.; Stones, W.; Dean, T. What is the impact of contraceptive methods and mixes of contraceptive methods on contraceptive prevalence, unmet need for family planning, and unwanted and unintended pregnancies? An overview of systematic reviews. University of Portsmouth, Portsmouth, UK (2011) 132 pp.

What is the impact of contraceptive methods and mixes of contraceptive methods on contraceptive prevalence, unmet need for family planning, and unwanted and unintended pregnancies? An overview of systematic reviews.

Published 1 January 2011