Background: Untreated depression during pregnancy may have adverse outcomes for the mother and her child. Screening for depression in the general pregnant population is thus recommended. The Edinburgh Depression Scale (EDS) is widely used for postpartum depression screening. There is no consensus on which EDS cutoff values to use during pregnancy. The aim of the current study was to examine the predictive validity and concurrent validity of the EDS for all three trimesters of pregnancy. Methods: In a large unselected sample of 845 pregnant women, the sensitivity, specificity, and validity of the EDS were evaluated. The Composite International Diagnostic Interview (depression module) was used to examine the predictive validity of the EDS. The anxiety and somatization subscales of the Symptom Checklist 90 (SCL-90) were used to examine its concurrent validity. Only women with a major depressive episode were considered as cases. Results: The prevalence of depression decreased toward end term: 5.6%, 5.4%, and 3.4%. The EDS scores also decreased toward end term, while the SCL-90 subscale anxiety scores increased. The EDS showed high test-retest reliability and high concurrent validity with the SCL-90 anxiety and somatization subscales. The area under the receiver operating characteristic curve was high and varied between 0.93 and 0.97. A cutoff value of 11 in the first trimester and that of 10 in the second and third trimesters gave the most adequate combination of sensitivity, specificity, and positive predictive value. Conclusions: The EDS is a reliable instrument for screening depression during pregnancy. A lower cutoff than commonly applied in the postpartum period is recommended. (c) 2011 Elsevier Inc. All rights reserved.