Few studies have focused on anxiety disorders in the perinatal period. While various studies have measured levels of anxiety or distress during pregnancy, most studies have relied upon self-report questionnaires to assess for anxiety.  In contrast, few studies have used standardized diagnostic criteria to determine the prevalence of anxiety disorders in pregnant populations.   In a recent study, Buist and colleagues studied the prevalence and course of generalized anxiety disorder (GAD) in a prospectively ascertained population of pregnant women.

Women were recruited from obstetric services throughout Connecticut and Western Massachusetts to participate in the Yale Pink and Blue study. All women with a history in the last five years of major depressive disorder (MDD) or post traumatic stress disorder (PTSD), or antidepressant use in the last year were invited to participate. One out of every three women who did not have these characteristics was recruited to participate as controls.  A total of 9525 women were screened and 2793 women were enrolled before their 17th week of pregnancy.

Women were interviewed face to face at enrollment and contacted again by telephone at 30 weeks of pregnancy and again at 8 weeks postpartum.  Interviews included the depressive disorder, panic disorder and GAD modules of the World Mental Health Composite International Diagnostic Interview.  GAD was defined according to DSM-IV criteria, with the exception that symptoms required a minimum of one month rather than six months.

The researchers observed that 9.5% of the cohort suffered from GAD at some point in the pregnancy. At entry into the study, 8% of the women retrospectively met criteria for a diagnosis of GAD in the six months prior to pregnancy. In pregnancy, the highest rates of GAD were observed in the first trimester (7%). Only 2% of women met criteria for GAD in the second trimester, and 3% in the third trimester.

Previous history of GAD was the strongest predictor of GAD during pregnancy; women with 4 or more episodes were about 7 times more likely to experience GAD during pregnancy than women with no history of GAD. Decreased levels of social support, less education, and history of child abuse also increased the risk of GAD during pregnancy.

When compared to other studies which have assessed anxiety during pregnancy, this study shows a much lower prevalence of anxiety symptoms.  This may be attributed to variations in recruitment strategies and methodology, as well as the fact that the current study used diagnostic interviews to assess for anxiety.  Studies which have demonstrated higher rates of anxiety have used self report questionnaires, such as the Hospital Anxiety and Depression Scale. One important limitation of this study is the potential confounding effect of antidepressant use which may have ameliorated symptoms of GAD; antidepressants were used by 12% of the women at some time point in pregnancy or after delivery.

Similar to previous studies, this study observed a decrease in anxiety symptoms across pregnancy.  The authors hypothesized that this may be due to the hormonal effects of pregnancy.

Ruta Nonacs, MD PhD

Buist A, Gotman N, Yonkers KA.  Generalized anxiety disorder: course and risk factors in pregnancy.  J Affect Disord. 2011; 131(1-3):277-83