Discrepancy between knowledge and practice in folic acid supplementation for NTD prevention: a mixed-methods study of Chinese women

Abstract Background Neural tube defects (NTDs) remain a major preventable cause of congenital disability worldwide. Existing evidence suggests a persistent gap between awareness and actual supplementation behaviors among women of childbearing age. Aims To assess folic acid-related knowledge and supplementation behaviors among women of childbearing age and to explore the knowledge–practice gap. Methods A mixed-methods study was conducted from June to September 2024. In the quantitative phase, a study-specific questionnaire was administered online to a convenience sample of 5,741 women aged 18–49 years recruited from different regions of mainland China. Folic acid-related knowledge and supplementation behaviors were assessed. Univariable and multivariable logistic regression analyses were used to examine the association between knowledge score and correct folic acid supplementation. In the qualitative phase, semi-structured interviews guided by the Health Belief Model were conducted with 18 pregnant women. Qualitative data were analyzed using directed content analysis, and the quantitative and qualitative findings were integrated through a joint display. Results Among the 5,741 survey participants, 5,490 (95.6%) knew that folic acid prevents NTDs, but only 3,594 (62.6%) knew the correct timing and 2,949 (51.4%) knew the recommended daily dose. Among the 4,470 women with pregnancy or pregnancy-planning experience, 3,858 (86.3%) had obtained folic acid, 3,708 (83.0%) had taken it, and 1,281 (28.7%) adhered to the full regimen. Knowledge score was significantly associated with adherence (adjusted OR = 1.493, 95% CI: 1.43–1.56). The qualitative analysis identified barriers related to perceived susceptibility, perceived severity, perceived benefits, perceived obstacles, and cues to action. Integration of the findings suggested that limited knowledge of the recommended timing and dosage, insufficiently individualized health information, and brief provider counseling may contribute to suboptimal supplementation practices. Conclusion Among the women participating in this study, awareness of the general preventive role of folic acid was high, but knowledge of the recommended timing and dosage and adherence to the complete supplementation regimen were substantially lower. Higher knowledge scores were associated with greater odds of correct supplementation. Preconception health education should provide specific, individualized, and theory-informed guidance on when, how much, and how long folic acid should be taken.