Neural tube defects are among the most common birth defects worldwide. Folic acid intake from one month before to three months after conception reduces the likelihood of neural tube defects by at least 50%. Since 1995, several campaigns have been organised in the Netherlands which resulted in 51% of pregnant women using folic acid supplements during the entire recommended period in the northern part of the Netherlands in 2005. Our research question was to gain insight into the current prevalence and factors associated with inadequate pregnancy-related use of folic acid supplements.Data from the DELIVER study were used, which is a population-based cohort study.Twenty midwifery practices across the Netherlands in 2009 and 2010.In total 5975 pregnant women completed a questionnaire covering items on sociodemographic and lifestyle factors, including folic acid intake.Of our study population, 55·5% (3318/5975) used folic acid supplements before conception. Several sociodemographic and lifestyle factors were associated with no preconception use of folic acid, of which non-Western ethnicity and not having a partner had the largest effect size.In the Netherlands, the folic acid intake before conception is suboptimal and has not improved over recent years. Fortification of staple foods with folic acid should be reconsidered as it would provide a more effective means of ensuring an adequate intake, especially for those groups of women who are unlikely to plan their pregnancies or to receive or respond to health promotion messages.