Depressive symptoms at two months after miscarriage: interpreting study findings from an epidemiological versus...

We identify two study designs used to investigate psychiatric symptoms following reproductive loss. One design examines psychiatric outcomes in a single cohort of bereaved women; the other compares psychiatric outcomes in bereaved and non-bereaved cohorts. We employ the findings from one study of depressive symptoms following miscarriage to exemplify these designs and inferential differences in causal inferences that can be drawn. We interviewed a cohort of 114 women at 6-8 weeks after miscarriage and a cohort of 318 community women not recently pregnant. Depressive symptoms were assessed with the Center for Epidemiologic Studies Depression (CES-D) Scale. Among miscarrying women, the mean level of depressive symptoms was substantially elevated above that in the community cohort (adjusted difference in means between cohorts, 4.9, 95% confidence interval [CI] 2.3-7.4). Among miscarrying women, 20.2% were highly symptomatic (CES-D 30+), as compared with 10.1% among community women (adjusted odds ratio [OR] 2.8, 95% CI 1.4-5.6). However, in contrast to findings from the same study concerning depressive reactions at 2 weeks after loss, the impact of miscarriage on depressive symptoms at 6-8 weeks was markedly greater for younger women and possibly for women with a history of prior reproductive loss, but otherwise did not vary with number of living children, marital status, ethnicity or educational level. We conclude that miscarrying women first seen at their 6- to 8-week post miscarriage gynecologic visit are likely to be more depressed on average than otherwise comparable women who have not experienced a recent reproductive loss. Factors that moderate the impact of miscarriage may vary with time since loss. Enhanced recognition of the implications of study design for research inferences may help bring greater clarify and uniformity to findings from future investigations in this field.