Prevalence and predictors of periconceptional folic acid uptake--prospective cohort study in an Irish urban obstetric population

BACKGROUND: Neural tube defects (NTDs) are severe abnormalities of the central nervous system that occur as a result of abnormal development in the third and fourth weeks of gestation. Studies have shown that periconceptional folic acid (FA) can reduce both the incidence and recurrence of NTDs.

METHODS: A cohort study was carried out using the electronic hospital booking records of women delivering in a large Dublin maternity hospital between 2000 and 2007. Logistic regression analyses were performed to measure the associations between maternal factors and optimal FA use.

RESULTS: Of the 61,252 women in the cohort, 85% reported taking FA at some point during the periconceptional period; however, only 28% took FA as recommended. Factors associated with taking the recommended amount of FA included nulliparity [adjusted OR: 1.35 (95% CI: 1.28-1.43)], early booking (<12 weeks) [OR: 1.24 (95% CI: 1.17-1.31)], increasing maternal age (e.g. 30-34 years) [OR: 1.39 (95% CI: 1.30-1.48)], private health care [OR: 4.32 (95% CI: 4.1-4.6)] and fertility treatment [OR: 2.88 (95% CI: 2.44-3.40)]. Factors associated with taking less than recommended or no FA included unplanned pregnancy [OR: 0.08 (0.07-0.08)], lower socio-economic status (e.g. unemployed) [OR: 0.63 (95% CI: 0.55-0.71)], non-Irish nationality [OR: 0.82 (0.74-0.90)] and smokers [OR: 0.51 (95% CI: 0.47-0.55)].

CONCLUSIONS: Social, demographic and economic factors have an important influence on the FA uptake. Vulnerable groups who report limited uptake of FA need to be specifically targeted in future Public Health campaigns and further consideration needs to be given to the debate on food fortification in countries where this is currently not available.