News - Folic acid in pregnancy may ease post-natal depression
The government recommends that all women planning pregnancy take 400mcg folic acid daily to help protect against neural tube defects, such as spina bifida. However, new research carried out in Bristol suggests that folic acid supplements during pregnancy may also help protect against post-natal depression.
Dr Sarah Lewis of Bristol University and her team wanted to explore the relationship in pregnant women by investigating whether high folate intake during pregnancy might offer protection against depression during pregnancy and afterwards. Their research is thought to be the first ever longitudinal study of folic acid supplementation and perinatal depression.
The study drew on data from 6,809 women who had taken part in the Avon Longitudinal Study of Parents and Children (ALSPAC), a population-based study conducted in the UK involving women who were expecting a baby between April 1991 and December 1992. They looked at the association between self-reported depressive symptoms at 18 and 32 weeks of pregnancy and at eight weeks, eight months and 21 months post partum; and self-reported folic acid supplementation at 18 and 32 weeks gestation.
When they analysed the results, they found no strong evidence linking self-reported folic acid intake to a reduce risk of self-reported depressive symptoms during pregnancy or in the first eight months after giving birth. However, they did note a link later on, as folic acid supplementation appeared to exert a protective effect against increased depressive symptoms between eight and 21 months after giving birth.
This effect was particularly pronounced in women with the methylenetetrahydrofolate reductase (MTHFR) C677T genotype, a genetic trait that is known to influence folate metabolism and methylation. The change in depression score for the women with this genotype from eight to 21 months was 0.66 among those not taking supplements, compared with -1.02 among those taking supplements at 18 weeks of pregnancy.
“Low folate is unlikely to be an important risk factor for depression during pregnancy and for post-partum depression, but it may be a risk factor for depression outside pregnancy, especially among women with the MTHFR C677T TT genotype,” wrote Dr Lewis in a report published in the European Journal of Clinical Nutrition.
The timescale for an observed effect is significant because without adequate supplementation, concentrations of maternal serum folate decrease gradually from the fifth month of pregnancy. They remain low for several months after the birth, meaning that women who become pregnant again within a short space of time may not rebuild serum folate to optimum pre-pregnancy levels.
Lewis SJ et al. Folic acid supplementation during pregnancy may protect against depression 21 months after pregnancy, an effect modified by MTHFR C677T genotype. Eur J Clin Nutr.