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

Knowledge and practices of preconception care among rural Japanese women: findings from a mixed methods investigation

BACKGROUND

Preconception care is not widespread in Japan and there is a pressing need to improve the practice. The present study assessed the knowledge and behavior of preconception care among women to seek effective intervention. Our research questions were: 1) How much do women know about preconception care? 2) How much are they practicing preconception care and what are the information sources of their behavior? 3) Do the women's preconception care behavior associated with accurate knowledge?

METHODS

The research was conducted in a rural town in central Japan. Using an exploratory sequential mixed methods design, we undertook interviews, developed a survey based on the qualitative results, and then conducted a survey. The interviews explored how preconception care was perceived and practiced in women of childbearing age. The survey was designed to investigate the knowledge of preconception care among women with and without pregnancy experience, their practice behavior of preconception care, and whether the behavior is associated with knowledge.

RESULTS

The participants were 13 for the interview and 232 for the survey. They had limited access to preconception care recommendations and advice for specific actions was given by obstetricians and gynecologists after pregnancy. There was a large gap in knowledge about preconception care between parous and nulliparous women, especially about the need for folic acid supplementation. Practices that were manageable in their daily lives, such as cessation of smoking and alcohol, diet, and weight management, were considered common sense. In contrast, recommended practices that require medical attention, such as screening for sexually transmitted diseases and cervical cancer, tended to be less accurately known and practiced. Participants' sources of information about preconception care were the Internet, family and friends and mass media.

CONCLUSION

In rural Japan, women of childbearing age lack knowledge about preconception care, especially before their first pregnancy. Primary care providers should try outreach to schools and women's groups in the community, promote information sharing among family and close friends, and utilize information technology to enhance the knowledge and practice of preconception care.

Maternal dietary folate intake with folic acid supplements and wheeze and eczema in children aged 2 years in the Japan Environment and Children’s Study

Maternal intake of folic acid supplements is reportedly associated with the risk of early-onset allergies in offspring. However, only a few studies have considered the intake of both folic acid supplements and dietary folate. Here, the relationship between maternal intake of folic acid supplements and allergic symptoms such as wheeze and eczema in offspring was analyzed while considering dietary folate intake. We examined 84,361 mothers and 85,114 children in the Japan Environment and Children’s Study. The participants were divided into three groups depending on maternal folic acid supplementation (“no use,” “occasional use,” and “daily use”). Each group was then subdivided into three groups based on total folic acid and dietary folate intake. Outcomes were determined considering the wheeze and eczema status of each child at the age of 2 years. The status was based on the International Study of Asthma and Allergies in Childhood. It was found that 22.1% of the mothers took folic acid supplements daily. In contrast, 56.3% of the mothers did not take these supplements. Maternal intake of folic acid supplements was not associated with wheeze and eczema in the offspring. In contrast, only dietary folate intake was positively associated with wheeze at the age of 2 (adjusted odds ratio, 1.103; 95% confidence interval, 1.003–1.212). However, there is no scientific evidence of a biological mechanism that clarifies this result. Potential confounders such as other nutrition, outdoor/indoor air pollution, and genetic factors may have affected the results. Therefore, further studies on the association between maternal intake of folic acid and allergic symptoms at the age of 3 or above are needed to confirm the results of this study.

Trial registration

UMIN Clinical Trials Registry (number: UMIN000030786)

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.

Prenatal folic acid supplementation and autism spectrum disorder in 3-year-old offspring: the Japan environment and children's study

OBJECTIVE

We evaluated the relationship between prenatal folic acid supplementation and autism spectrum disorder (ASD) in 3-year-old offspring.

METHODS

We used data from the Japan Environment and Children's Study, a nationwide prospective birth cohort study. We analyzed the data to determine the association between folic acid supplement use and the incidence of ASD in offspring, and classified participants into three groups based on the time of initiation of folic acid supplementation, as follows: (1) preconception users of folic acid supplements and (2) post-conception users, and (3) non-users. The dietary folate intake of study participants was also classified into three groups (<200 µg, 200 µg to <400 µg, ≥400 µg).

RESULTS

Overall, 361 offspring of 96,931 participants with single pregnancies were diagnosed with ASD (0.37%). A total of 7,046 participants (7.3%) used folic acid supplements before conception, 29,984 (30.9%) took them after detection of pregnancy, and 59,901 (61.8%) never received them. Multivariate logistic regression analyses demonstrated no association between prenatal folic acid supplementation and ASD in offspring (preconception use: adjusted odds ratio [AOR], 1.189; 95% confidence interval [CI], 0.819-1.727 and post-conception use: AOR, 1.072; 95% CI, 0.840-1.368); additionally, no association was observed with the use of folic acid supplements and/or multivitamin supplements (preconception use: AOR, 1.273; 95% CI, 0.921-1.760 and post-conception use: AOR, 1.132; 95% CI, 0.885-1.449). Moreover, no significant association was observed in participants with combined prenatal supplement use and dietary folate intake.

CONCLUSIONS

Maternal use of folic acid supplements from the pre- or post-conception period was not significantly associated with ASD in 3-year-old offspring in Japan. Evaluation of the dietary folate intake from preconception also showed no significant association.

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

More evidence is available for maternal intake, absorption, distribution, tissue specific concentrations, and pregnancy outcomes with folic acid (fortification/supplementation) during preconception - first trimester. This Quality Improvement prevention review used expert guidelines/opinions, systematic reviews, randomized control trials/controlled clinical trials, and observational case control/case series studies, published in English, from 1990 to August 2021. Optimization for an oral maternal folic acid supplementation is difficult because it relies on folic acid dose, type of folate supplement, bio-availability of the folate from foods, timing of supplementation initiation, maternal metabolism/genetic factors, and many other factors. There is continued use of high dose pre-food fortification 'RCT evidenced-based' folic acid supplementation for NTD recurrence pregnancy prevention. Innovation requires preconception and pregnancy use of 'carbon one nutrient' supplements (folic acid, vitamin B12, B6, choline), using the appropriate evidence, need to be considered. The consideration and adoption of directed personalized approaches for maternal complex risk could use serum folate testing for supplementation dosing choice. Routine daily folic acid dosing for low-risk women should consider a multivitamin with 0.4 mg of folic acid starting 3 months prior to conception until completion of breastfeeding. Routine folic acid dosing or preconception measurement of maternal serum folate (after 4-6 weeks of folate supplementation) could be considered for maternal complex risk group with genetic/medical/surgical co-morbidities. These new approaches for folic acid oral supplementation are required to optimize benefit (decreasing folate sensitive congenital anomalies; childhood morbidity) and minimizing potential maternal and childhood risk.

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)

We determine the prevalence and trends of open neural tube defects (ONTDs) during 1991 to 2019 at the "Dr. Juan I. Menchaca" Civil Hospital of Guadalajara (Mexico). Also, details of potential risks were obtained in 662 newborns, including those 143 patients with anencephaly and open spina bifida (OSB) classified as isolated (cases) and 519 controls. Data were analyzed using multivariable logistic regression. Among 267 201 live births during the study period, 336 were born with ONTDs, yielding an overall prevalence of 12.6 per 10 000. After folic acid (FA)-related programs began in Mexico (2003-2019), only OSB showed a decline of 20.6%. For anencephaly, associated risks included relatives with neural tube defects (NTDs) (adjusted odds ratio [aOR]: 67.9, 95% confidence interval [95% CI]: 11.3-409.8), pre-pregnancy body mass index (BMI) ≥25 kg/m² (aOR: 2.6, 95% CI: 1.1-6.0), insufficient gestational weight gain (aOR: 3.0, 95% CI: 1.3-7.1), parity ≥4 (aOR: 3.2, 95% CI: 1.3-7.7), and exposure to analgesic/antipyretic drugs (aOR: 9.0; 95% CI: 2.5-33.0). For OSB, associated risks included consanguinity (aOR: 14.0, 95% CI: 3.5-55.9), relatives with NTDs (aOR: 22.4, 95% CI: 4.5-112.9), BMI ≥25 kg/m² (aOR: 2.5, 95% CI: 1.6-4.2), insufficient gestational weight gain (aOR: 1.9, 95% CI: 1.1-3.1), and exposures to hyperthermia (aOR: 2.3, 95% CI: 1.2-4.3), common cold (aOR: 6.8, 95% CI: 3.6-12.7), and analgesic/antipyretic drugs (aOR: 3.6, 95% CI: 1.3-10.0). Our high rate probably results from exposures to preventable risks, most related to FA, indicating a need for strengthening existing FA-related programs in Mexico.

Folic acid prescribed to prenatal and postpartum women who are also prescribed antiepileptic drugs in Japan: Data from a health administrative database

BACKGROUND

The aim of this study was to evaluate the prevalence of folic acid (FA) prescription to prenatal and postpartum women who have also been prescribed antiepileptic drugs (AED) in Japan.

METHODS

The data set used in this study included women covered by health insurance between 2005 and 2016. The prevalence of FA prescriptions between 180 days before pregnancy and 180 days postpartum was determined from a large administrative database, with the FA prescription classified according to dose and timing.

RESULTS

For 33,941 women meeting our eligibility criteria, the mean maternal age at delivery was 32.3 years. At least one AED was prescribed to 225 of 33,941 women between 180 days before pregnancy and 180 days postpartum. FA was prescribed to 32 of 225 women (14.2%) during the same period. FA was prescribed to 8.8% of women with AED within 90 days before pregnancy and to 19.8% during the first trimester. FA was prescribed to 10.9% during the first 30 days after conception, all of whom were prescribed FA before the pregnancy. The maximum FA dose prescribed within 90 days before pregnancy was 5 mg/day for 5 of 12 women (41.7%) and >5 mg/day for 4 of 12 women (33.3%). The maximum FA dose prescribed during the first trimester was 5 mg/day for 14 of 22 women (63.6%) and >5 mg/day for 8 of 22 women (36.4%).

CONCLUSIONS

The concurrent prescription of FA with AEDs in Japan was an uncommon therapeutic approach both before and during pregnancy.