It's estimated that as many as 13% of pregnant women have a major depressive disorder. Although the causes of and risk factors for postpartum depression have received much attention, it's also important to understand the risk factors for depression during pregnancy.

A recent review of 57 studies published between 1980 and 2008 examined 20 possible risk factors for antepartum depression that could be clinically assessed during normal obstetric visits. Because of the heterogeneity of studies, which had widely varying study parameters, patient populations, and measures, metaanalysis proved impossible; the researchers therefore looked at effect size (small, medium, and large) in studies employing bivariate and multivariate analyses. After bivariate analysis, anxiety during pregnancy; stress from negative life events, such as a death or divorce; a personal history of depression; insufficient social support, particularly from the woman's partner; a history of domestic violence; unintended pregnancy; a poor-quality intimate relationship; being on Medicaid rather than having private insurance; and lower socioeconomic status, specifically income, education, and unemployment, were all associated with a higher risk of antepartum depression. After multivariate analysis, only life stress, social support, and domestic violence continued to have significant associations.

The American College of Obstetricians and Gynecologists (ACOG) recommends screening pregnant women for depression during each trimester, and obstetric practitioners, including nurses, are in the perfect position to assess their patients. Many report, however, receiving no training in such assessment. There are tools to help, such as ACOG's Antepartum Record (http://bit.ly/bkQjhF), which contains reminder boxes that address histories of depression and domestic violence.-Tammy Worth