The results of a review of studies involving more than 19,000 patients suggest that rates of depression during pregnancy are high. This might be especially true during the second and third trimesters.
"Current estimates of the prevalence of depression during pregnancy vary widely," Dr. Thomas R. Einarson and colleagues from the University of Toronto, Ontario, report in Obstetrics and Gynecology. "A more precise estimate is required to identify the level of disease burden and develop strategies for managing depressive disorders."
To investigate, the researchers identified a number of relevant observational studies and surveys from a variety of databases. Ultimately, a total of 21 articles involving 19,284 patients were included in their analysis.
Among instruments employed were the Beck Depression Inventory and the Edinburgh Postnatal Depression Scales. Structured interviews were also used alone and in combination with these instruments. Structured interviews found lower rates of depression than did the Beck Depression Inventory, but not the Edinburgh Postnatal Depression Scale.
Based on their analysis, they estimate that the prevalence of depression was 7.4 percent in the first trimester, 12.8 percent in the second and 12.0 percent in the third trimester of pregnancy.
Overall rates did not differ significantly across trimesters. However, the team points out that the lower rate of depression in the first trimester, "must be interpreted with caution," because few studies were available for this period.
In light of these "substantial" rates of depression, the investigators conclude that "clinical and economic studies to estimate maternal and fetal consequences are needed."