Periconceptional folic acid intake and disturbing factors: A single-center study in Japan.

We investigated folic acid (FA) intake and disturbing factors in pregnant women who visited our center in 2017. Among 1531 pregnant women, 45.1% of women initiated FA supplementation before pregnancy. The risk of failure of supplementation was significantly lower among women of ≥35 (adjusted odds ratio [aOR] 0.43) and 30-34 years of age (aOR: 0.59) in comparison to women of <30 years of age, and among those conceived with timing/artificial insemination of husband (aOR 0.47) and in vitro fertilization/intracytoplasmic sperm injection (aOR 0.32) in comparison to those conceived naturally. The risk among those with 1 (aOR 1.44) or ≥2 previous deliveries (aOR 2.75) was significantly higher in comparison to nulliparous women. Young, multiparous women, and those with natural conception should be targeted to promote preconceptional FA intake.