UNLABELLED: Studies in the general population have proposed links between nutrition and depression, but less is known about the perinatal period. Depletion of nutrient reserves throughout pregnancy and delayed postpartum repletion could increase the risk of perinatal depression. We examined the relationships of plasma folate and vitamin B12 concentrations during pregnancy with perinatal depression. At 26th-28th weeks of gestation, plasma folate and vitamin B12 were measured in women from the GUSTO mother-offspring cohort study in Singapore. Depressive symptoms were measured with the Edinburgh Postnatal Depression Scale (EPDS) during the same period and at 3-month postpartum. EPDS scores of ≥15 during pregnancy or ≥13 at postpartum were indicative of probable depression. Of 709 women, 7.2% (n = 51) were identified with probable antenatal depression and 10.4% (n = 74) with probable postnatal depression. Plasma folate concentrations were significantly lower in those with probable antenatal depression than those without (mean ± SD; 27.3 ± 13.8 vs 40.4 ± 36.5 nmol/L; p = 0.011). No difference in folate concentrations was observed in those with and without probable postnatal depression. In adjusted regression models, the likelihood of probable antenatal depression decreases by 0.69 for every unit variation (increase) in folate (OR = 0.69 per SD increase in folate; 95% CI: 0.52, 0.94). Plasma vitamin B12 concentrations were not associated with perinatal depression. Lower plasma folate status during pregnancy was associated with antenatal depression, but not with postnatal depression. Replication in other studies is needed to determine the direction of causality between low folate and antenatal depression.
CLINICAL TRIAL REGISTRY: NCT01174875.