The epidemiology of infertility in the North East of Scotland

BACKGROUND: There is a perception that the prevalence of infertility is on the rise. This study aimed to determine the current prevalence of infertility in a defined geographical population, ascertain changes in self-reported infertility over time and identify risk factors associated with infertility. METHODS: A postal questionnaire survey of a random population-based sample of women aged 31-50 years was performed in the Grampian region of Scotland. Questions addressed the following areas: pregnancy history, length of time taken to become pregnant each time, whether medical advice had been sought and self-reported exposure to factors associated with infertility. RESULTS: Among 4466 women who responded, 400 (9.0%) 95% CI 8.1, 9.8 had chosen not to have children. Of the remaining 4066 women, 3283 (80.7%) 95% CI 79.5, 82.0 reported no difficulties in having children and the remaining 783 (19.3%) 95% CI 18.1, 20.5 had experienced infertility, defined as having difficulty in becoming pregnant for more than 12 months and/or seeking medical advice. In total 398 (9.8%) 95% CI 8.9, 10.7 women had primary infertility, 285 (7.0%) 95% CI 6.2, 7.8 had secondary infertility, 100 (2.5%) 95% CI 2.0, 2.9 had primary as well as secondary infertility. A total of 342 (68.7%) and 208 (73.0%) women with primary and secondary infertility, respectively, sought medical advice and 202 (59.1%) and 118 (56.7%) women in each group subsequently conceived. History of pelvic surgery, Chlamydial infection, endometriosis, chemotherapy, long-term health problems and obesity were associated with infertility. In comparison with a similar survey of women aged 46-50 from the same geographical area, the prevalence of both primary infertility (>24 months) 70/1081, (6.5%) versus 68/710 (9.6%) P = 0.02 and secondary infertility 29/1081 (2.7%) versus 40/710 (5.6%) P = 0.002 were significantly lower. CONCLUSIONS: Nearly one in five women attempting conception sampled in this study experienced infertility, although over half of them eventually conceived. Fertility problems were associated with endometriosis, Chlamydia trachomatis infection and pelvic surgery, as well as obesity, chemotherapy and some long-term chronic medical conditions. There is no evidence of an increase in the prevalence of infertility in this population over the past 20 years.