Delaying mandatory folic acid fortification policy perpetuates health inequalities: results from a retrospective study of postpartum New Zealand women

Abstract

Internationally, poor periconceptional folic acid uptake has been associated with lower socioeconomic status, minority ethnicity status and unintentional pregnancy. The aim of this study was to describe the extent to which a proposed bread fortification mandate would modify these associations. A retrospective survey of postpartum women in hospitals and birthing centres across New Zealand was conducted using a self-administered questionnaire. Details on supplement use and bread intake in the periconceptional period, and maternal socio-demographic and obstetric characteristics were obtained. Criteria for the adequate intake of folic acid through proposed mandatory fortification were the habitual consumption of three or more slices of bread/day (118-150 μg folic acid/day) in the month prior to conception, and during the first trimester of pregnancy. Of the 968 women approached, 758 (78%) agreed to participate. Thirty-three percent of women reported having used folic acid supplements as recommended during the periconceptional period. The proportion of women who would have achieved adequate folic acid intake increased to 59% with mandatory fortification. Socio-demographic predictors of poor folic acid intake from supplements, including younger maternal age, increasing parity, minority ethnicity status, lower education and less income, were rendered either non-significant or appreciably attenuated when mandatory fortification was modelled. Notably, the fully adjusted odds ratio for pregnancy planning was reduced from 17.24 [95% confidence interval (CI): 8.13-36.55] to 2.61 (95% CI: 1.73-3.93; both P< 0.001). Few women comply with periconceptional folic acid recommendations and thus the maximal prevention of neural tube defects is still far from being attained. Data from this retrospective study demonstrate that mandatory fortification benefits segments of the population less likely to use supplements. This finding has compelling policy implications in countries yet to mandate the folic acid fortification of a staple food.