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

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.