Taking folic acid before and during early pregnancy can greatly reduce the risk of neural tube defects (NTD), such as spina bifida. However, a study of birth registry data has found that the prevalence of NTD has not declined in Europe over the past 20 years, despite recommendations for folic acid supplementation.
The analysis included around 12.5 million births between 1991 and 2011, during which time the prevalence of non-chromosomal NTD ranged from 8.5 to 10.1 per 10,000 births. However, the researchers report in The
BMJ (online, 24 November 2015)
that there was no obvious downward trend, and the total prevalence was similar in 2011 to 1991.
They suggest that European countries should therefore consider mandatory fortification of foods with folic acid, which has proved effective in reducing rates of NTD elsewhere.
 Khoshnood B, Loane M, de Walle H et al. Long term trends in prevalence of neural tube defects in Europe: population based study. BMJ 2015;351:h5949. doi:10.1136/bmj.h5949