Preconception folic acid supplementation use and the occurrence of neural tube defects in Japan: A nationwide birth cohort study of the Japan Environment and Children's Study

Abstract

We evaluated the relationship between preconception folic acid supplementation and the occurrence of neural tube defects (NTDs) in offspring, using data from the Japan Environment and Children's Study (a nationwide prospective birth cohort study) database. Of 92 269 participants with single pregnancies, 74 cases (offspring or fetuses) had NTDs, including 32 cases of spina bifida, 24 cases of anencephaly, and 19 cases of encephalocele. A total of 7634 participants (8.27%) used preconception folic acid supplementation, and of these, 621 (0.67%) also took in dietary folic acid at ≥480 μg/day. Multivariate logistic regression analyses demonstrated no association between preconception folic acid supplementation and NTDs in offspring or fetuses (odds ratio [OR] 0.622; 95% confidence interval [CI]: 0.226-1.713). Moreover, the participants who combined preconception folic acid supplement use with dietary folic acid intake ≥480 μg/day demonstrated no incidence of NTDs in offspring or fetuses. Our analysis is limited by the absence of the data on the daily amount of supplementary folic acid intake, requiring careful attention to the interpretation. Additional surveys are required in Japan to resolve those limitations for further comprehensive assessment.

Prevalence of open neural tube defects and risk factors related to isolated anencephaly and spina bifida in live births from the “Dr. Juan I. Menchaca” Civil Hospital of Guadalajara (Jalisco, Mexico)

“…For the 29‐year period, prevalence in our hospital for ONTDs was of 12.6 per 10 000 live births (Table 1). This is notably higher compared with other prevalences based on data limited to live‐born from countries such as the United States, 22 Canada, 23 Norway, 24 and Japan, 25 which range from 2.2 to 6.9 per 10 000 live births; despite the fact that in those countries around two‐thirds of cases do not achieve birth because are electively terminated after prenatal NTDs diagnosis. It also coincides with reports indicating that our co‐nationals living in the US have intriguingly an elevated rate of NTDs in comparison with other ethnicities, 8,26 which ranges from 3.9 to 5.8 per 10 000 live births.…”

Maternal folic acid and multivitamin supplementation: International clinical evidence with considerations for the prevention of folate-sensitive birth defects

“…Folic acid combination in multivitamin supplements has been shown to reduce additional congenital anomalies. Case-control cohorts, after FA fortification, highlight the decrease in folate sensitive congenital anomaly frequencies ( Czeizel, 1996 , Jahanbin et al, 2018 , Ingrid Goh et al, 2006 , Goh and Koren, 2008 , Johnson and Little, 2008 , Lowry et al, 2019 , Morris et al, 2018 , Nishigori et al, 2019 , Kondo et al, 2019 , McDonnell et al, 2018 , Mao et al, 2017 , Liu et al, 2019 , Liu et al, 2018 , Liu et al, 2018 , Kurdi et al, 2019 , Poletta et al, 2018 , Li et al, 2013 , Godwin et al, 2008 , Canfield et al, 2005 , Canfield et al, 2009 , Ray et al, 2002 , Wilcox et al, 2007 ).…”

“…Table 8 summarizes the routine evidenced-based FA supplementation dosing alone, if no maternal serum FA monitoring is considered in the prevention process using Table 1 , Table 2 ( MRC Vitamin Study Research Group, 1991 , Czeizel and Dudás, 1992 , Shaw et al, 1995 , Werler et al, 1993 , Cawley et al, 2017 , Castillo-Lancellotti et al, 2013 , Moore et al, 2003 , Bonnette et al, 1998 , Caudill et al, 1997 , Czeizel, 1996 , Jahanbin et al, 2018 , Ingrid Goh et al, 2006 , Goh and Koren, 2008 , Johnson and Little, 2008 , Lowry et al, 2019 , Morris et al, 2018 , Nishigori et al, 2019 , Kondo et al, 2019 , McDonnell et al, 2018 , Mao et al, 2017 , Liu et al, 2019 , Liu et al, 2018 , Liu et al, 2018 , Kurdi et al, 2019 , Poletta et al, 2018 , Li et al, 2013 , Godwin et al, 2008 , Canfield et al, 2005 , Canfield et al, 2009 , Ray et al, 2002 , Wilcox et al, 2007 ). The Appendix provides additional detail for routine verses personalized FA supplementation dosing considerations.…”

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

“…Regarding the rate of preconceptional FA intake, the rate in our study (45.1%) was much higher in comparison to previous reports from Japan (8.0%-23.1%). [7][8][9][10] This may be due to the fact that the pregnant women treated at our center included more women with an advanced maternal age (≥35 years old), who were primiparous or who underwent an ART technique than other facilities. In addition, our dataset was the most recent one among previous reports, since the prevalence of adequate FA use increases year over year in Japan.…”