Folic acid supplements during pregnancy may not only reduce the risk of birth defects but also protect the children from congenital heart defects, says a new study from the Netherlands.

Children of women who took at least 400 micrograms per day during pregnancy were about 20 per cent less likely to develop congenital heart defects (CHDs), compared to children of women who did not take additional folic acid, according to findings in the European Heart Journal.

“Our results support the hypothesis that additional periconceptional folic acid use reduces CHD risk in infants,” wrote the researchers, led by Ingrid van Beynum from the Radboud University Nijmegen Medical Centre.

“Use of periconceptional folic acid supplements was related to about a 20 per cent reduction in the prevalence of any CHD. Given the relatively high prevalence of CHD worldwide, our findings are important for public health,” they added.

An overwhelming body of evidence links folate deficiency in early pregnancy to increased risk of neural tube defects (NTDs) – most commonly spina bifida and anencephaly – in infants.

This connection led to the 1998 introduction of public health measures in the US and Canada, where all grain products are fortified with folic acid – the synthetic, bioavailable form of folate.

Preliminary evidence indicates that the measure is having an effect with a reported 15 to 50 per cent reduction in NTD incidence. A total of 51 countries now have some degree of mandatory fortification of flour with folic acid.

However, similar measures in other countries have been opposed by concerns that the folate/folic acid may mask vitamin B12 deficiency, which leads to a form of neurological problems.

The new study supports the benefits to the children of ensuring adequate folic acid/ folate during pregnancy. The Dutch researchers analysed data from over 3,000 mothers and infants for their case-control study.

Children of women who took additional folic acid, defined as a daily single supplement or as a multivitamin containing a folic acid dose of at least 400 micrograms, were found to have an 18 per cent lower risk of CHDs.

In a subgroup analysis, additional folic acid was associated with a 38 per cent reduction in isolated septal defects, said the researchers.

With such obvious benefits for the child, the researchers said that their findings may have important implications for public health.

Source: European Heart Journal, 12-03-2009