Factors influencing contraception choice and use globally: a synthesis of systematic reviews.

<bold>Background: </bold>Unintended pregnancy has a huge adverse impact on maternal, child and family health and wealth. There is an unmet need for contraception globally, with an estimated 40% of pregnancies unintended worldwide.<bold>Methods: </bold>We systematically searched PubMed and specialist databases for systematic reviews addressing contraceptive choice, uptake or use, published in English between 2000 and 2019. Two reviewers independently selected and appraised reports and synthesised quantitative and qualitative review findings. We mapped emergent themes to a social determinants of health framework to develop our understanding of the complexities of contraceptive choice and use.<bold>Findings: </bold>We found 24 systematic reviews of mostly moderate or high quality. Factors affecting contraception use are remarkably similar among women in very different cultures and settings globally. Use of contraception is influenced by the perceived likelihood and appeal of pregnancy, and relationship status. It is influenced by women's knowledge, beliefs, and perceptions of side effects and health risks. Male partners have a strong influence, as do peers' views and experiences, and families' expectations. Lack of education and poverty is linked with low contraception use, and social and cultural norms influence contraception and expectations of family size and timing. Contraception use also depends upon their availability, the accessibility, confidentiality and costs of health services, and attitudes, behaviour and skills of health practitioners.<bold>Interpretation: </bold>Contraception has remarkably far-reaching benefits and is highly cost-effective. However, women worldwide lack sufficient knowledge, capability and opportunity to make reproductive choices, and health care systems often fail to provide access and informed choice. [ABSTRACT FROM AUTHOR]