Trends in primary and secondary infertility prevalence since 1990: a systematic analysis of demographic and reproductive health surveys

BackgroundStudies of infertility prevalence are sparse and use definitions that are not comparable. However, infertility prevalence may be inferred by applying a consistent algorithm to demographic and reproductive health survey data. Using household survey data, we estimate infertility prevalence and trends, from 1990 to 2010, by country and region.MethodsWe developed an algorithm to infer infertility prevalence from commonly collected demographic data by analysing Demographic and Health Survey data. We applied the algorithm to 277 demographic and reproductive health surveys. We corrected for biases arising from the use of incomplete information on past union status and contraceptive use. We used a Bayesian hierarchical model to estimate trends and prevalence of infertility in 190 countries and territories.FindingsIn 2010, among women 20–44 years of age who were exposed to the risk of pregnancy, 1·9% (95% uncertainty interval 1·7–2·2) were unable to attain a livebirth (primary infertility). Out of women who have had at least one livebirth and were exposed to the risk of pregnancy, 10·5% (9·5–11·7) were unable to have another child (secondary infertility). Infertility prevalence was highest in south Asia, sub-Saharan Africa, north Africa and the Middle East, central and eastern Europe, and central Asia. Levels of infertility in 2010 were similar to those in 1990 in most world regions, apart from declines in primary and secondary infertility in sub-Saharan Africa and primary infertility in south Asia (posterior probability ≥0·99).InterpretationIndependent from worldwide declines in the preferred number of children and from population growth, we found little evidence of changes in infertility over two decades, apart from the regions of sub-Saharan Africa and south Asia. Further research is needed to identify the aetiological causes of these patterns and trends.FundingThis study was partially funded by the Bill & Melinda Gates Foundation, Subcontract No. 498744 of the Global Burden of Diseases, Injuries, and Risk Factors Study 2010 (University of Washington). The results in this paper are prepared independently of the final estimates of the Global Burden of Disease Study.