Occurrence of fertility problems presenting to primary care: population-level estimates of clinical burden and socioeconomic inequalities across the UK

What are the age-specific incident rates of clinically recorded fertility problems in women aged 1549 years and how do they vary by socioeconomic group and geographic area. The incident rate of recorded fertility problems was highest in women age 3034 years: about 1 of women per annum. Overall rates did not vary by socioeconomic group; however, age-specific rates varied substantially by socioeconomic deprivation quintile; among younger women, deprivation was associated with higher infertility rates. The rates of infertility in the UK range from 2 to 26. Infertility definitions and denominators vary widely, and most current evidence is based on questionnaire studies that are subject to recall, reporting and selection bias. The current paper presents population-based estimates of clinically recorded fertility problems in women of reproductive age and the variation by age and socioeconomic deprivation quintile across different regions of the UK, using a nationally representative cohort of women that is larger than any previous study. Although infertility overall does not vary by socioeconomic status, consultation for fertility problems is closely related to socioeconomic patterns of womens age at first conception, demonstrating that many couples have pre-existing, rather than specifically age-related, infertility. This cohort study used data from The Health Improvement Network, a computerized primary care database of anonymized patient records from general practices across the UK, with prospective health records on over 1.7 million women between 1990 and 2010. Our cohort included 1 776 746 women of reproductive age (age 1549 years) who contributed one or more years of active general practice registration. We estimated rates of new clinically recorded fertility problems in these women using medical records and medications exclusively used to treat infertility. We assessed variation in age-specific incidence by socioeconomic deprivation quintile and geographic area using Poisson regression. The rate of incident recorded fertility problems was highest in women in the 3034 year age group (10.9 per 1000 person-years), which equates to approximately 1 of women per annum in this age group. Lowest rates were in women in the 1519 and 4549 year age groups (0.7 and 0.4 per 1000 person-years, respectively). Overall rates did not vary by socioeconomic group, measured using quintiles of the Townsend index. Age-specific rates, however, varied substantially with socioeconomic deprivation quintile (P-value for interaction 0.0001) such that up to age 25, women with more deprivation had more recorded fertility problems [rate ratio (RR) comparing most to least deprived 5.6, 95 confidence interval (CI) 4.47.2 at 1520 years of age]. This reversed from age 25 to 39, when women with more deprivation had fewer recorded fertility problems (RR 0.6 95 CI 0.50.6 at age 3034). After age 40, there was no socioeconomic gradient in absolute rates. This is by far the largest population-based study to estimate clinically recorded fertility problems in women and the first in the UK to assess variation across such a broad age group from 15 to 49 years. Our data, however, did not capture women who experience difficulty in conceiving, but do not consult their general practitioner (GP) regarding fertility problems. Compared with existing estimates, our measures of the extent and distribution of recorded fertility problems in primary care are more useful for GPs, primary care trusts and policy makers for the planning and delivery of fertility services. We have shown a high burden of infertility with little geographic variation; however, the significant burden in young, more deprived women needs recognition in light of age restrictions for treatment availability for infertility in the UK. Not only does treatment access need to be universal and more equitably allocated across socioeconomic groups, but also more resources are required to reduce fertility problems by targeting modifiable risk factors. There was no direct source of funding for this research work. N.N.D. completed the work as part of an M.Sc., which was funded by Developing Solutions Scholarship provided by theInternational Office, University of Nottingham/. J.W. is supported by a University of Nottingham/National Institute for Health Research (NIHR)/Senior Clinical Research Fellowship. Not applicable.