Folate awareness and the prevalence of neural tube defects in South Australia, 1966–2007

Abstract

To ascertain changes in: women's knowledge of the role of folic acid in the prevention of neural tube defects (NTDs); intake of folic acid among pregnant women; and prevalence of NTDs in South Australia. Computer-assisted telephone interviews of South Australian households from 1994 to 2007 over a period encompassing a statewide folate promotion campaign (1994-1995), continuing folate promotion, as well as the introduction of voluntary folate fortification of foods (1996); ascertainment of the total prevalence of NTDs from births and terminations of pregnancy from 1966 to 2007. Changes in women's knowledge of the role of folic acid in the prevention of NTDs; changes in the prevalence of NTDs. From 1994 to 2006 and 2007, knowledge about the role of folic acid increased from 25% to 77% (P < 0.001) and knowledge that folic acid needs to be taken in the periconceptional period increased from 12% to 39% (P < 0.001). The proportion of pregnant women who increased their periconceptional intake of folate rose from 61% in 1998 to 81% in 2006 and 2007 (P < 0.001), with significant increases in the consumption of fortified cereals (from 15% to 29%) and folic acid tablets (from 37% to 64%). The total prevalence of NTDs fell from 2.06 per 1000 births in 1986-1990 to 1.23 per 1000 births in 2002-2007 (relative risk, 0.60; 95% CI, 0.48-0.74; P < 0.001). Folate promotion and voluntary fortification of certain foods with folic acid were associated with increased awareness of the role of periconceptional folic acid, increased folate consumption and a reduction in the prevalence of NTDs in South Australia by 40% (95% CI, 26%-52%).