Protective effect of micronutrients used to treat antenatal depression on rates of postnatal depression at six months: A secondary analysis of NUTRIMUM

Abstract

Background: Antenatal depression is a debilitating pregnancy condition and risk factor for postnatal depression, with estimates suggesting 39–92 % of women with antenatal depression will have postnatal depression. Aims: This study investigated rates of postnatal depression in women who had symptoms of antenatal depression and were treated antenatally with micronutrients (vitamins and minerals). Methods: Self-reported (Edinburgh Postnatal Depression Scale (EPDS)) and clinician-rated depression (Montgomery and Åsberg Depression Rating Scale (MADRS)) were assessed at six months postnatally in mothers who participated in the NUTRIMUM trial, a double-blind randomised placebo-controlled trial that investigated if micronutrients could treat symptoms of antenatal depression. At study entry, women were 12–24 weeks gestation, medication-free, and moderately depressed (≥ 13 EPDS). Depression scores were obtained six months post-birth from 61 (80.3 %) of eligible participants (those who took micronutrients during pregnancy) and compared to scores at study entry. Results: Mothers at six-month follow-up had significant reduction in their depression scores relative to study entry (Cohen's d > 2). Rates of depression, based on both EPDS (≥13; 14 %) and MADRS (≥20; 8 %), were substantially less than expected based on presence of antenatal depression, and on par with general population rates. Mothers who switched or added psychiatric medication postnatally (n = 6), had had fewer days of antenatal micronutrient exposure than those who didn't switch, and had higher 6-month depression scores. Postnatal micronutrient supplementation was not necessary to reduce postnatal depression. Conclusion: This study highlights the protective and symptom reduction potential of antenatal micronutrient supplementation to prevent postnatal depression in mothers at higher risk.