Is peripartum magnesium sulfate associated with a reduction in postpartum depressive symptoms

BACKGROUND The prevention of postpartum depression is an important area of investigation given its association with major maternal and neonatal sequelae, yet few evidence-based treatments to reduce the frequency of postpartum depression are used. Recent data suggest that N-methyl-D-aspartate receptor antagonists may lead to rapid improvement of depressive symptoms lasting up to 2 weeks. We hypothesized that the N-methyl-D-aspartate receptor antagonist magnesium sulfate would elicit antidepressant effects subsequent to its receipt by women receiving peripartum seizure prophylaxis for a hypertensive disorder of pregnancy. OBJECTIVE This study aimed to compare the frequency of depressive symptoms at 2 weeks and 6 weeks after delivery between women who did and did not receive peripartum magnesium sulfate for a hypertensive disorder of pregnancy. STUDY DESIGN This prospective cohort study included women with a hypertensive disorder of pregnancy at ≥34 weeks’ gestation with singleton gestations. Magnesium sulfate for seizure prophylaxis was administered at the obstetrician's discretion. The Quick Inventory of Depressive Symptomatology survey was administered before hospital discharge and again at 2 weeks and 6 weeks after delivery to assess for postpartum depressive symptoms. The primary outcome for this study was the change in Quick Inventory of Depressive Symptomatology score from baseline to 2 weeks after delivery, which was analyzed both continuously and categorically (any symptom worsening vs stability or improvement). Secondary outcomes included the change in Quick Inventory of Depressive Symptomatology score from baseline to 6 weeks after delivery and the proportion of women who experienced an increase in Quick Inventory of Depressive Symptomatology score at 6 weeks after delivery. RESULTS Of the 342 women enrolled, 39% (n=134) received magnesium sulfate. Compared with women who did not receive magnesium, women who received magnesium had a significantly smaller change in their mean Quick Inventory of Depressive Symptomatology score (0.6±3.4 vs 1.6±3.0; P=.015) and also were less likely to have an increase in Quick Inventory of Depressive Symptomatology score at 2 weeks after delivery (52% vs 67%; P=.022). These differences were not present at 6 weeks after delivery. After controlling for potential confounders, women who received magnesium continued to have a lower odds of having an increased Quick Inventory of Depressive Symptomatology score from baseline at 2 weeks after delivery than women who did not receive magnesium (adjusted odds ratio, 0.88; 95% confidence interval, 0.78–0.98). CONCLUSION Peripartum magnesium was associated with less of an exacerbation in depressive symptoms in the immediate postpartum period. Given the implications of postpartum depression on maternal and child health and the lack of existing prophylaxis, randomized trials should examine this novel potential prophylactic therapy.