Association between duration of folic acid supplementation during pregnancy and risk of postpartum depression.

The risk of postpartum depression is influenced by demographic factors, socio-economic status, family history, social support, cultural factors, inflammation, hormones, nutrients, and other biological factors. The nutrients that have been previously implicated in postpartum depression include folate, vitamin B12, calcium, iron, selenium, zinc, and polyunsaturated fatty acids. 

Folate participates in the production of s-adenosyl methionine (SAMe) through homocysteine methylation and is essential for the biosynthesis of monoamine neurotransmitters (serotonin, dopamine, and norepinephrine). Whereas folate deficiency has been associated with depression in the general population, the results of studies related to folic acid and postpartum depression have been inconsistent.  

Methods

A study published by Yan and colleagues in the journal Nutrients (2017) evaluated the association between duration of folic acid supplementation during pregnancy and the prevalence of postpartum depression in a cohort of Chinese women. Self-reported questionnaires were used to assess folic acid intake and depressive symptoms. Of 1592 women, 60% took folic acid for less than 6 months during pregnancy, and 40% took folic acid for 6 months or more. The overall prevalence of postpartum depression in the cohort was 29.4%. 

The risk of postpartum depression is influenced by several factors.

Results

Women who took folic acid supplements for 6 or more months during pregnancy had a significantly lower prevalence of depression at 6-12 weeks postpartum than those who took folic acid for less than 6 months (25% vs. 32%; p<.05). Women with longer duration of folic acid intake tended to be older, more highly educated, and have higher household income. Propensity score matching was used to minimize the effect of these and other compounding variables, yielding similar results. Logistic regression revealed that longer duration of folic acid supplementation was independently associated with postpartum depression risk (OR=0.76; 95% CI, 0.59-0.98; p<.05). 

Conclusions

The dosage of folic acid supplementation was not evaluated in this study, but the Chinese government recommends prenatal intake of 400 mcg per day. The authors conclude that folic acid supplementation for 6 months or more during pregnancy may reduce the risk of postpartum depression.  

Yan, J., Liu, Y., Cao, L., Zheng, Y., Li, W., & Huang, G. (2017). Association between duration of folic acid supplementation during pregnancy and risk of postpartum depression. Nutrients, 9(11).