While we are becoming more attentive to screening for depressive symptoms during pregnancy and the postpartum period, we may not always ask about a history of trauma, especially when a woman has had what most would consider an “uncomplicated” pregnancy. A recent study, however, indicates that a history of trauma may be a risk factor for depression during pregnancy.

In this report, 374 pregnant women aged 20–34 years were recruited from a hospital-based obstetrics service caring for a predominantly low-income, inner-city population.  Diagnostic interviews and questionnaires were administered at 18 and 32 weeks of gestation and at 6 weeks and 6 months postpartum. Lifetime exposure to and details of traumatic events were also recorded.

A traumatic event was defined according to criterion A1 of the DSM-IV diagnostic criteria for PTSD: “exposure to an extreme traumatic stressor involving direct personal experience of an event that involves actual or threatened death or serious injury, or other threat to one’s physical integrity; or witnessing an event that involves death, injury, or a threat to the physical integrity of another person; or learning about unexpected or violent death, serious harm, or threat of death or injury experienced by a family member or other close associate.”

39% of the sample reported at least one traumatic event.  All types of antecedent trauma were associated with developing PTSD.  However, only the following categories of trauma were associated with an increased risk of antenatal but not postpartum depression:  childhood sexual abuse (OR = 2.47), someone close experiencing violence (OR = 2.19), and the unexpected death or illness of someone close (OR = 2.15).

In addition, a clear dose-response effect of trauma on antenatal depression was observed; women who experienced 3 or more traumatic events had a 4-fold increased risk (OR = 4.34) of antenatal depression compared to women with no trauma history.

This study indicates that trauma history is a strong predictor of depression during pregnancy.  Interestingly, the researchers did not observe an association between trauma and risk for postpartum depression. The authors hypothesize that the link between trauma exposure and depression vulnerability may be different for pregnant and postpartum women.

In this study, the timing of the traumatic event and its proximity to pregnancy did not appear to influence risk for depression.  In fact, abuse that took place during childhood was one of the strongest predictors of risk for depression during pregnancy.  The authors hypothesize that the persistent psychobiological and physiologic changes that take place as a result of exposure to trauma alter one’s sensitivity to subsequent stressors.  Specifically, trauma-exposed individuals show persistent dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis.  During a normal pregnancy, there is a substantial increase in levels of the stress hormone cortisol and an apparent diminished responsiveness of the HPA axis to acute stress. In women with a history of trauma, dysregulation of the HPA axis may result in an increased vulnerability to depression in this setting.

The authors also point out that there are important treatment implications, citing research which demonstrates that a history of childhood trauma may negatively affect treatment response.  Women with trauma histories who experience depression may need different types of interventions than women without a trauma history.  While there is more to learn about effective interventions in various populations of reproductive aged women, routine screening for trauma history during pregnancy may help us to identify women who are at increased risk for mood and anxiety disorders during pregnancy and the postpartum period.

Ruta Nonacs, MD PhD

Robertson Blackmore E, et al. Antecedent Trauma Exposure and Risk of Depression in the Perinatal Period.  J Clin Psychiatry 2013;74(10):e942–e948.