Objectives: To estimate the national prevalence and analyse the factors associated with preconceptional folic acid supplementation, including maternal sociodemographic characteristics, region of residence, birth control use and chronic diseases requiring medical care before conception.
Design: Cross-sectional population-based study.
Setting: All maternity units in France.
Population: A nationally representative sample of women giving birth in 2010 (n = 12,646).
Methods: Data came from mothers' interviews 2-3 days after delivery. Statistical analyses included multivariable logistic regressions.
Main outcome measure: Folic acid supplementation starting at least 1 month before conception.
Results: 14.8% (95% confidence interval [95% CI] 14.2-15.4) of women used folic acid before pregnancy; this percentage varied from 10.4% to 18.7% across regions. Supplementation was more frequent in primiparae, French citizens, women with higher educational levels and those needing medical monitoring or treatment before conception. Women who stopped contraception to become pregnant (75% of our population) used folic acid more often (intrauterine device or implant: 19%, pill: 17%, other methods which did not need medical monitoring: 17%) than other women (7%). The adjusted odds ratios were 3.3 (95% CI 2.6-4.3) for intrauterine device and implant, 2.2 (95% CI 1.8-2.6) for pill and 1.9 (95% CI 1.5-2.4) for other methods, compared with women who did not use birth control.
Conclusion: The absence of preconceptional folic acid supplementation for most women, even those needing consultations with healthcare professionals before pregnancy, shows that campaigns to promote folic acid supplementation should address not only women but also healthcare professionals involved in birth control and obstetric care before pregnancy.
Keywords: Chronic diseases; fertility treatments; folic acid; maternal characteristics; preconception; pregnancy planning; region.
© 2013 Royal College of Obstetricians and Gynaecologists.