Suicide is a leading cause of maternal mortality in the United States. According to a 2017 study from California, drug-related deaths (3.68 per 100,000 person-years) and suicides (1.42 per 100,000 person-years) accounted for nearly 20% of all maternal deaths.   Previous studies have indicated that suicidal ideation is relatively common among pregnant women; however, we have much less information on the occurrence of self-harm and suicide during pregnancy.  A recent study published in the British Journal of Psychiatry looks at the prevalence of self-harm in pregnant and not-pregnant women.  Self-harm gives us a better estimate of suicidality than suicidal ideation, as self-harm is associated with an up to 50 times increased risk for suicide in women.

In a retrospective cohort study using the Clinical Practice Research Datalink and Pregnancy Register (1990 to 2017) from the United Kingdom, Hope and colleagues identified over 2 million women aged 15–45 years who were  linked to 1,102,040 pregnancies and their outcomes.  They identified self-harm events and mental illness diagnoses from the clinical record and calculated the rate of self-harm during discrete non-perinatal, pregnant and postpartum periods. 

The researchers identified a total of 57,791 self-harm events. They observed that the risk for self-harm decreased by about 50% during pregnancy (2.07 versus 4.01 events/1,000 person-years) with an adjusted hazard ratio (aHR) of 0.53.  However, risk for self-harm was about the same in pregnant and non-pregnant 15- to 19-year-olds (aHR 0.95).  The risk was also significantly reduced among women with mental illness (aHR = 0.40). In fact, although women with mental illness are more likely to self-harm than women without, their reduction in risk during pregnancy was greater than observed in women without mental illness. 

After delivery, self-harm risk increased, peaking at 6–12 months postpartum (aHR = 1.08, 95% CI 1.02–1.15).  The women who were at greatest risk for self-harm included younger women and women with a pregnancy loss or termination.

Why is Risk for Self-Harm Lower During Pregnancy?

This is one of the largest studies to date looking at suicidality during pregnancy and the postpartum populations.  The findings are consistent with previous studies, documenting lower risk for self-harm during pregnancy and increased risk of self-harm following delivery.

Although some hypothesize that the hormonal changes associated with pregnancy may be beneficial to women’s mental health and may contribute to decreased risk of self-harm, this explanation is not supported by our early studies demonstrating high rates of relapse among pregnant women with unipolar depression and bipolar disorder.  

Although future studies are required to better understand this finding, I suspect that the structure and support many women experience during pregnancy may have beneficial effects.  This may be particularly true for women with mental health issues.  It is likely that during pregnancy women have more social contacts and feel less socially isolated than at other times.  In addition, the increased focus on maternal well-being may increase attention to self-care and may facilitate the early identification o f breakthrough symptoms during pregnancy, factors which may mitigate risk for recurrence of illness and self-harm.

These factors may not, however, benefit younger mothers, as this study did not observe a reduction in risk of self-harm in pregnant women between the ages of 15 and 19.  In this population, it is likely that other factors, including unplanned pregnancy, being single, and living in poverty, may affect risk for self-harm.  Further investigation is required to better understand how to support this population and to mitigate risk for self-harm.  

Ruta Nonacs, MD PhD

Hope H, Pierce M, Osam CS, Morgan C, John A, Abel KM. Self-harm risk in pregnancy: recurrent-event survival analysis using UK primary care data.  Br J Psychiatry. 2022 Mar 1:1-7. 



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