[Peri-pregnancy folic acid supplementation must be improved].

The correct usage of folic acid (FA) supplements to prevent neural tube defects (NTDs) increased from 28% in 1996 to 50% in 2005 and remained stable until 2009. Recent data from national birth defect registries show a decrease of NTD prevalence from 13.2 (per 10,000) in 1997 to 8.