Clinical studies have found higher occurrences of anxiety and depression in women who experience fertility problems. However, the relationship between common mental symptoms and sub-/infertility should also be investigated in the normal population.

In a valid N=15,000 sample of women (mean age=36 years, s.d.=8.4, range 19-49) in the Nord-Trøndelag Health Study 1995-97 (HUNT 2), the relationship of anxiety- and/or depression with fertility problems was explored by means of logistic regression analysis. Psychological symptoms were measured by the 14-item Hospital Anxiety and Depression Scale (HADS) (cut-off=14+, i.e. 90th percentile). Sub-/infertility was defined as having ever tried to get pregnant for more than one year without success. Analyses were adjusted for age, education, civil status, somatic conditions, parity, and gynaecological surgery.

In all, 2,058 (14%) of women were sub- or infertile. Mean HADS total score was 7.8 (s.d. 5.73, range 0-35) in this group and 7.1 (s.d. 5.43, range 0-39) in the group without fertility problems. Odds ratios for fertility problems in the group that scored above HADS cut-off were 1.26 (95% CI=1.09; 1.45), p=0.002 in the crude analysis and 1.13 (95% CI=0.97;1.31), p=0.123 in the adjusted analysis.

The effect size for the relationship between common mental disorders and fertility problems in this epidemiological study was weak. However, it may represent a more true estimate of the relationship than findings from earlier clinical studies, as such clinical studies may be biased due to differences between help-seeking patients and healthy controls.