Maternal use of folic acid and multivitamin supplements and infant risk of birth defects in Norway, 1999-2013

Preconceptional micronutrient adequacy among women in Greece: a prospective epidemiological study

INTRODUCTION

The importance of micronutrient intake during the preconceptional and early pregnancy period for both maternal and fetal outcomes is well-known, however, relevant data are not available for Greek pregnant women. The aim of the present study is to delineate the nutritional status preceding conception among a representative cohort of Greek pregnant women.

METHODS

This was a prospective study of pregnant women from routine care, recruited at 11+0-13+6 gestational weeks, between December 2020 and October 2022, at the 3rd Department of Obstetrics and Gynecology, Aristotle University of Thessaloniki, Greece. Eligible participants for the study included healthy pregnant women aged 20 years or older, possessing a proficient understanding of the Greek language, and not engaged in specific nutritional programs. A validated Food Frequency Questionnaire was applied to gather information regarding nutritional habits in the last 6 months prior to conception. The consumption of nutrients was compared to the reference intake levels suggested by the European Food Safety Authority. Further analyses between different participants' subgroups were performed.

RESULTS

Overall, 1100 pregnant women (mean age: 32.4 ± 4.9 years) were enrolled. Almost all examined micronutrients' intake was significantly different from dietary reference values. Furthermore, nutrient adequacy ratio was below 60% in 6 out of 22 micronutrients examined, and Mean Adequacy Ratio was 93%. However, Mean Adequacy Ratio is characterized by extreme variance between the examined values. Iodine, folic acid, potassium, and vitamin D intake levels were significantly lower than the recommended intake levels (p < .001 for all), while vitamin K and niacin (p < .001 for both) were consumed in great extent. Sodium median intake, without calculating extra salt addition also exceeded the reference value levels (p = .03). Notably, magnesium intake exceeded the upper safety limits in 12.4% of the sample.

CONCLUSION

Potential inadequacies in important micronutrients for uneventful pregnancy outcomes have been revealed.. Special attention is needed for magnesium to balance possible toxicity with evident benefits.

Frequency of gastroschisis and omphalocele and possible influence of maternal folic acid supplementation. A narrative review

There is an increase in the worldwide prevalence of congenital abdominal wall defects (CAWD), with gastroschisis (GS) and omphalocele (OC) being the most common. It is widely accepted that folic acid supplementation (FAS) in the maternal diet decreases the incidence of anomalies such as neural tube defects, but there is controversy regarding the possible beneficial role for other congenital malformations. Several epidemiological studies raise controversy regarding a possible relationship between vitamin supplementation with the occurrence of abdominal wall malformations. The aim of the present study is to obtain an updated review of the global frequency of CAWD in neonates and the relationship with FAS in the mothers. For this we have carried out a systematic search of epidemiological studies in different article databases between 2011 and 2022. The analysis of 25 studies conducted in different countries where cases of OC and/or GS are registered directly or together with other congenital defects shows that 60% inquire into the relationship of FAS with the incidence of CAWD. Half of them proposes a beneficial effect of FAS and the other half find no association, concluding that there is no unanimous evidence that FAS in the maternal diet decreases the incidence of CAWD. However, it seems that an influential factor to take into account is the nutritional habits of the mothers.

Maternal periconceptional folic acid supplementation and risk for fetal congenital genitourinary system defects

BACKGROUND

Taking folic acid supplementation could reduce the risk of neural tube defects for offspring in the maternal periconceptional period, but the relationship between folic acid use and other birth defects remains unclear, such as genitourinary system birth defects.

METHODS

The data from a Prenatal Health Care System and Birth Defects Surveillance System in Tongzhou, Beijing, China, were collected from 2013 to 2018. We adjusted for differences in characteristics between comparison groups using propensity score inverse probability weighting and assessed associations with Poisson regression modeling.

RESULTS

A total of 65,418 live births and stillbirths were included, and there were 194 cases with congenital genitourinary defects among them. The prevalence of genitourinary system birth defects was 29.2 (34.9) per 10,000 for FA/MMFA users (nonusers). Compared to nonusers, FA/MMFA users had a lower risk for genitourinary system birth defects (adjusted risk ratio [aRR] 0.81, 95% confidence interval [CI] 0.67, 0.98), and for hypospadias (aRR 0.55, 95% CI 0.40, 0.76).

CONCLUSIONS

FA or MMFA supplementation during the maternal periconceptional period could reduce the risk for genitourinary system birth defects in offspring. More mechanisms should be explored for the protective effect.

IMPACT

Folic acid (FA) or multiple micronutrients containing folic acid (MMFA) supplementation during the maternal periconceptional period could reduce the risk for genitourinary system birth defects in offspring. Maternal FA/MMFA supplementation during the periconceptional period may reduce the risk for hypospadias.

Updated EUROCAT guidelines for classification of cases with congenital anomalies

BACKGROUND

Precise and correct classification of congenital anomalies is important in epidemiological studies, not only to classify according to etiology but also to group similar congenital anomalies together, to create homogeneous subgroups for surveillance and research. This paper presents the updated EUROCAT (European surveillance of congenital anomalies) subgroups of congenital anomalies and the updated multiple congenital anomaly (MCA) algorithm and provides the underlying arguments for the revisions.

METHODS

The EUROCAT methodology is described. In addition, we show how we validated the revised EUROCAT subgroups and MCA algorithm, which are both based on the International Classification of Diseases (ICD10/ICD9) codes.

RESULTS

The updated EUROCAT subgroups and the updated MCA algorithm are described in detail and the updated version is compared to the previous versions.

CONCLUSION

The EUROCAT subgroups and MCA algorithm provide a standardized and clear methodology for congenital anomaly research and epidemiological surveillance of congenital anomalies in order to facilitate the identification of teratogenic exposures and to assess the impact of primary prevention and prenatal screening policies. The EUROCAT subgroups and MCA algorithm are made freely available for other researchers via the EUROCAT Database Management Software.

Folic acid supplements and perinatal mortality in China

Introduction

Periconceptional use of multivitamins containing folic acid prevents external major birth defects, especially neural tube defects. We aimed to explore the effects of maternal folic acid supplementation alone on perinatal mortality with or without external major birth defects plus neural tube defects.

Methods

From the China-US Collaborative Project for Neural Tube Defects Prevention, we identified 222, 303 singleton pregnancies with detailed information on periconceptional folic acid use, defined as folic acid supplementary before the last menstrual date until to the end of the first trimester. Perinatal mortality included stillbirths after 20 weeks' gestation and early neonatal deaths within 7 days of delivery.

Results

Among the fetuses or infants of women who did not take folic acid, the rate of perinatal mortality was 2.99% and 1.62% at least 20 weeks' gestation in the northern and southern regions. Among the fetuses or infants of the women with periconceptional use of folic acid, the rates were 1.85% and 1.39% in the northern and southern region. The estimated relative risk for perinatal mortality [adjusted risk ratio (RR), 0.72; 95% confidence interval (CI), 0.61- 0.85], stillbirth (adjusted RR, 0.78; 95% CI, 0.64-0.96), early neonatal mortality (adjusted RR, 0.61; 95% CI, 0.45-0.82), and neonatal death (adjusted RR, 0.64; 95% CI, 0.49-0.83) in northern China was significantly decreased in association with periconceptional folic acid supplementation. Compared with northern, there was a lesser effect in southern China.

Conclusion

Periconceptional intake of 400μg folic acid daily reduces the overall risk perinatal mortality, as well as the risk from external major birth defects and neural tube defects, especially in northern China.

Folate deficiency increases the incidence of dolutegravir-associated foetal defects in a mouse pregnancy model

BACKGROUND

Dolutegravir (DTG) is a recommended first-line regimen for all people with Human Immunodeficiency Virus (HIV) infection. Initial findings from Botswana, a country with no folate fortification program, showed an elevated prevalence of neural tube defects (NTDs) with peri-conceptional exposure to DTG. Here we explore whether a low folate diet influences the risk of DTG-associated foetal anomalies in a mouse model.

METHODS

C57BL/6 mice fed a folate-deficient diet for 2 weeks, were mated and then randomly allocated to control (water), or 1xDTG (2.5 mg/kg), or 5xDTG (12.5 mg/kg) both administered orally with 50 mg/kg tenofovir disoproxil fumarate 33.3 mg/kg emtricitabine. Treatment was administered once daily from gestational day (GD) 0.5 to sacrifice (GD15.5). Foetuses were assessed for gross anomalies. Maternal and foetal folate levels were quantified.

FINDINGS

313 litters (103 control, 106 1xDTG, 104 5xDTG) were assessed. Viability, placental weight, and foetal weight did not differ between groups. NTDs were only observed in the DTG groups (litter rate: 0% control; 1.0% 1xDTG; 1.3% 5xDTG). Tail, abdominal wall, limb, craniofacial, and bleeding defects all occurred at higher rates in the DTG groups versus control. Compared with our previous findings on DTG usage in folate-replete mouse pregnancies, folate deficiency was associated with higher rates of several defects, including NTDs, but in the DTG groups only. We observed a severe left-right asymmetry phenotype that was more frequent in DTG groups than controls.

INTERPRETATION

Maternal folate deficiency may increase the risk for DTG-associated foetal defects. Periconceptional folic acid supplementation could be considered for women with HIV taking DTG during pregnancy, particularly in countries lacking folate fortification programs.

FUNDING

This project has been funded by Federal funds from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, under Contract No. HHSN275201800001I and award #R01HD104553. LS is supported by a Tier 1 Canada Research Chair in Maternal-Child Health and HIV. HM is supported by a Junior Investigator award from the Ontario HIV Treatment Network.

Is the Tradeoff between Folic Acid or/and Multivitamin Supplementation against Birth Defects in Early Pregnancy Reconsidered? Evidence Based on a Chinese Birth Cohort Study

BACKGROUND

Several studies have reported conflicting results on the association between maternal exposure to folic acid (FA) and/or multivitamin (MV) supplements and the risk of birth defects (BDs), especially for different subtypes of BDs. The present study aimed to identify the association between maternal exposure to FA or/and MV and BDs in offspring.

METHODS

In the Chinese Birth Cohort Study initiated from 20 November 2017, 120,652 pregnant women completed follow-up until 20 August 2021. The participants were classified into four groups: without exposure to FA and MV, exposure to only FA, exposure to only MV, and exposure to FA and MV. Birth defects were coded by the International Classification of Diseases (ICD)-10. In order to explore the structural relationship between maternal FA or MV supplements and BDs, directed acyclic graphs were drawn. Then, an inverse probability treatment weighting was utilized to reduce the systematic differences in the baseline characteristics among the different groups. Lastly, a two-level mixed-effect log binomial regression analysis was used to estimate the relative risk (RR) value of the different subtypes of BDs under different exposures to FA and/or MV.

RESULTS

Compared with the maternal group without exposure to FA and MV, the RR values of nervous system defects, face, ear, and neck defects, limb defects, and CHDs in the maternal group with only FA supplementation were less than 1.0, but they were not statistically significant. The RR values of genitourinary defects, abnormal chromosomes, and oral clefts were more than 1.0, and they were also not statistically significant. However, the risk of genitourinary defects (RR: 3.22, 95% CI: 1.42-7.29) and chromosomal abnormalities (RR: 2.57, 95% CI: 1.16-5.73) in the maternal group with only MV supplementation increased more than those in the maternal group without exposure to FA and MV. In addition, the RR values of all subtypes of BDs in the maternal group with exposure to FA and MV were closer to 1.0 than those in maternal group with exposure to only MV, but they were not statistically significant.

CONCLUSIONS

It was indicated that the simultaneous supplementation of FA and MV in early pregnancy may have an interaction for the prevention of BDs and may have inconsistent effects for different subtypes of BDs. At the same time, excessive FA supplementation in pregnant women may increase the risk of BDs in their offspring. Although the mechanism is not clear, this evidence reminded us that more trade-offs are necessary for formulating strategies for the prevention of BDs with FA and/or MV supplementation in early pregnancy.

Vitamin Supplementation in Pre-Pregnancy and Pregnancy among Women-Effects and Influencing Factors in Romania

Introduction: The aim of the study was to identify the consumption of vitamin and folic acid supplements before and during pregnancy in a group of post-partum women (Romanian, Hungarian, and Roma) from Mureș County, Romania, and the influence of socio-economic and behavioral factors on the consumption of vitamins. Materials and Methods: This cross-sectional questionnaire-based study included 1278 post-partum women (during the three days of hospitalization for birth), average age 29.5, registered for giving birth in the three hospitals in Mureș County, 2015−2016. Results: In our sample, 69.58% of the interviewed women did not use any vitamin and folic acid supplements before pregnancy, while 30.70% did not use vitamin supplements during pregnancy. The lack of vitamin supplementation during pregnancy was associated with the low birth weight (<2500 g) of newborns (OR = 2.4, 95% CI [1.6−3.8]) and birth at under 36 weeks of gestation (OR = 0.5, 95% CI [0.2−0.8]). Conclusion: The use of vitamin supplements, including folic acid, continues to be deficient among Romanian women before getting pregnant, as well as during their pregnancy. We observed a lack of vitamin supplementation for pregnant women even if they were influenced by risk factors. This highlights the importance of promoting the benefits of vitamin supplementation equally among all subjects.

How Parental Predictors Jointly Affect the Risk of Offspring Congenital Heart Disease: A Nationwide Multicenter Study Based on the China Birth Cohort

Objective

Congenital heart disease (CHD) is complex in its etiology. Its genetic causes have been investigated, whereas the non-genetic factor related studies are still limited. We aimed to identify dominant parental predictors and develop a predictive model and nomogram for the risk of offspring CHD.

Methods

This was a retrospective study from November 2017 to December 2021 covering 44,578 participants, of which those from 4 hospitals in eastern China were assigned to the development cohort and those from 5 hospitals in central and western China were used as the external validation cohort. Univariable and multivariable analyses were used to select the dominant predictors of CHD among demographic characteristics, lifestyle behaviors, environmental pollution, maternal disease history, and the current pregnancy information. Multivariable logistic regression analysis was used to construct the model and nomogram using the selected predictors. The predictive model and the nomogram were both validated internally and externally. A web-based nomogram was developed to predict patient-specific probability for CHD.

Results

Dominant risk factors for offspring CHD included increased maternal age [odds ratio (OR): 1.14, 95% CI: 1.10–1.19], increased paternal age (1.05, 95% CI: 1.02–1.09), maternal secondhand smoke exposure (2.89, 95% CI: 2.22–3.76), paternal drinking (1.41, 95% CI: 1.08–1.84), maternal pre-pregnancy diabetes (3.39, 95% CI: 1.95–5.87), maternal fever (3.35, 95% CI: 2.49–4.50), assisted reproductive technology (2.89, 95% CI: 2.13–3.94), and environmental pollution (1.61, 95% CI: 1.18–2.20). A higher household annual income (100,000–400,000 CNY: 0.47, 95% CI: 0.34–0.63; &gt; 400,000 CNY: 0.23, 95% CI: 0.15–0.36), higher maternal education level (13–16 years: 0.68, 95% CI: 0.50–0.93; ≥ 17 years: 0.87, 95% CI: 0.55–1.37), maternal folic acid (0.21, 95% CI: 0.16–0.27), and multivitamin supplementation (0.33, 95% CI: 0.26–0.42) were protective factors. The nomogram showed good discrimination in both internal [area under the receiver-operating-characteristic curve (AUC): 0.843] and external validations (development cohort AUC: 0.849, external validation cohort AUC: 0.837). The calibration curves showed good agreement between the nomogram-predicted probability and actual presence of CHD.

Conclusion

We revealed dominant parental predictors and presented a web-based nomogram for the risk of offspring CHD, which could be utilized as an effective tool for quantifying the individual risk of CHD and promptly identifying high-risk population.

The association between folic acid supplementation and congenital heart defects: Systematic review and meta-analysis

Introduction:

Various trial and epidemiological studies consistently documented the association between maternal folic acid supplementations and neural tube defects. However, existing literatures revealed inconclusive findings about maternal periconceptional folic acid supplementations and the risk of congenital heart defects. Thus, the current systematic review and meta-analysis was aimed to estimate the pooled association between maternal periconceptional folic acid supplementations and congenital heart defects.

Methods:

Electronic searches of PubMed, Web of Science/Scopus, Cochrane library and Google Scholar databases were conducted to access the required studies published up to March 2021. Predetermined eligibility criteria were used for study selections. Data extraction were independently done on excel. STATA version 14 software was used to calculate the pooled effect size with 95% confidence intervals (95% CI) of maternal periconceptional folic acid supplementations on congenital heart defects using the DerSimonian and Laird random effects meta-analysis (random effects model). Statistical heterogeneity was checked using the Cochran Q test (chi-squared statistic), I2 statistic, and by visual inspection of the funnel plot.

Results:

A total of 37 studies of case–control, cohort and randomized controlled trial in nature were included in the review. The finding of the present systematic review and meta-analysis indicated that periconceptional folic acid supplementation significantly decreases the risk of congenital heart defects (risk ratio (RR), 0.79; CI, 0.71, 0.89). Both Cochrane Q test statistic (χ2 = 19.33, p = 0.962) and I2 test statistic (I2 = 0.0%, p = 0.962) did not reveal statistically significant heterogeneity among included studies. In this meta-analysis, traditional funnel plot, Begg’s funnel plot, Egger’s weighted regression (p = 0.13) as well as Begg’s rank correlation statistic (p = 0.676) revealed no evidence of publication bias.

Conclusion:

The present systematic review and meta-analysis found that maternal periconception folic acid supplementation was significantly associated with the risk of congenital heart defects. The risk of congenital heart defects was significantly reduced by 21% among those children of mothers who use periconceptional folic acid supplementations in high-income countries. We recommend that a large prospective study be conducted to investigate the association between maternal periconceptional folic acid supplementation and occurrence of congenital heart defect of various types, especially in the developing countries.

Trends and influencing factors of perinatal birth defects in Huai'an from 2008 to 2020

OBJECTIVE

To analyze the incidence, trends and related factors of birth defects in Huai'an from 2008 to 2020.

METHODS

The surveillance data from maternal and child health system of Huai'an from 2008 to 2020 and Huai'an Statistical Yearbook were used for analysis. Taking the annual change percentage and average annual change percentage (AAPC) as the main outcome indicators, the JoinPoint regression analysis was performed to estimate the changing trend of birth defects from 2008 to 2020. Spearman correlation analysis was used to examine the association between birth defects and birth rate, marriage rate, proportion of women with advanced maternal age.

RESULTS

During 2008 to 2020, a total of 3414 cases of neonatal birth defects occurred in Huai'an, with an incidence of 4.6‰ (3414/736 608). The rate of perinatal birth defects in Huai'an showed an increasing trend (AAPC=8.8%, t=3.2, P<0.01), and the year of 2016 was a significant changing point. Among 24 types of birth defects, the incidence of congenital heart disease rose and became the most prevalent defect, while the incidence of neural tube malformations such as anencephaly, encephalocele and spina bifida was declined. The incidence of birth defect was negatively correlated with the birth rate ( r=-0.751, P<0.01), not correlated with marriage rate ( r=-0.516, P>0.05), and positively correlated with the proportion of women with advanced maternal age ( r=0.726, P<0.01).

CONCLUSION

The incidence of birth defects in Huai'an shows an increasing trend from 2008 to 2020 with congenital heart disease as the most common type of birth defect, and the increase of birth defects incidence is closely related with the increase of the proportion of women with advanced maternal age.

Maternal periconceptional folic acid supplements use and fetus risk for limb defects

BACKGROUND

Associations between the periconceptional folic acid only (FAO) or multiple micronutrients containing folic acid (MMFA) supplementation and risk for limb defects are inconsistent.

OBJECTIVE

To explore the association between periconceptional folic acid supplements use and risk for limb defects, including clubfoot, polydactyly, syndactyly, and limb deficiencies.

METHODS

Data were derived from a cohort based on a pregnancy registry in a district of Beijing, China, from 2013 to 2018. Information on maternal periconceptional FAO and MMFA supplementation was collected via face-to-face interviews at first trimester. Pregnancy outcomes including limb defects were ascertained in livebirths, stillbirths, and elective pregnancy terminations and were recorded into the system. Propensity score methods were used to adjust for potential confounders.

RESULTS

A total of 63 969 women with a singleton delivery were included. The overall prevalence of limb defects was 47.5 per 10 000 (n = 63 969) singleton deliveries. Decreased prevalence of limb defects was found among FAO/MMFA users compared with women who did not take supplements (nonusers) (46.1 vs. 61.9 per 10 000 births, adjusted risk ratio [RR] 0.80, 95% confidence interval [CI] 0.56, 1.12). Compared with nonusers (n = 6462, 10.2%), women who took either FAO (n = 26 567, 42.0%) or MMFA (n = 30 259, 47.8%) had a lower risk for total clubfoot (RR 0.40, 95% CI 0.20, 0.84), and for isolated clubfoot (RR 0.41, 95% CI 0.17, 0.97). For other limb defects except clubfoot, FAO supplementation did not appear to be associated with reduced risk, while MMFA supplementation group had 30%-50% reduced risks for other limb defects. A lower risk for limb defects or isolated limb defects was found with MMFA supplementation when FAO supplementation was used as a control.

CONCLUSIONS

Maternal periconceptional supplements with either FAO or MMFA had inverse association with clubfoot in offspring, and MMFA was associated with lower risk for isolated limb defects compared with FAO.

Maternal periconceptional folic acid supplementation reduced risks of non-syndromic oral clefts in offspring

Maternal periconceptional folic acid supplementation (FAS) has been documented to be associated with decreased risk of nonsyndromic oral clefts (NsOC). However, the results remain inconclusive. In this population-based case–control study of 807 singletons affected by NsOC and 8070 healthy neonates who were born between October 2010 and September 2015 in Chengdu, China, we examined the association of maternal FAS with the risk of nonsyndromic cleft lip with or without cleft palate (NsCL/P), and cleft palate (NsCP). Unconditional logistic regression analysis was used to estimate the crude and adjusted odds ratios (ORs) and 95% confidential intervals (CI). Significant associations were found between maternal periconceptional FAS and decreased risk of NsCL/P (aOR = 0.41, 95% CI 0.33–0.51). This protective effect was also detected for NsCL (aOR = 0.42, 95% CI 0.30–0.58) and NsCLP (aOR = 0.41, 95% CI 0.31–0.54). Both maternal FAS started before and after the last menstrual period (LMP) were inversely associated with NsCL/P (before LMP, aOR = 0.43, 95% CI 0.33–0.56; after LMP, aOR = 0.41, 95% CI 0.33–0.51). The association between NsCP and maternal FAS initiating before LMP was also found (aOR = 0.52, 95% CI 0.30–0.90). The findings suggest that maternal periconceptional FAS can reduce the risk of each subtype of NsCL/P in offspring, while the potential effect on NsCP needs further investigations.

Folic acid supplementation and risk for fetal abdominal wall defects in China: results from a large population-based intervention cohort study

Folic acid (FA) can reduce the risk for selected birth defects other than neural tube defects. We examined whether FA has preventive effects against fetal abdominal wall defects (AWD) in a unique intervention cohort in China. Birth outcomes of 247 831 singleton births from a population-based cohort study with detailed pre-conceptional FA intake information were collected in China in 1993-1996. Information on births at 20 complete gestational weeks, including live births, stillbirths and pregnancy terminations, and all structural birth defects regardless of gestational week were recorded. The birth prevalence of omphalocele, gastroschisis and total fetal AWD was classified by maternal FA supplementation. The prevalence of total AWD was 4·30 per 10 000 births among women who took FA compared with 13·46 per 10 000 births among those who did not take FA in northern China and 6·28 and 5·18 per 10 000 births, respectively, in southern China. The prevalence of omphalocele was 0·54 per 10 000 births among women who took FA compared with 3·74 per 10 000 births among those who did not take FA in northern China and 1·79 and 1·44 per 10 000 births, respectively, in southern China. FA supplementation significantly prevented total AWD in multivariate analysis (relative risk 0·26, 95 % CI 0·11, 0·61) in northern China, although no preventive effect of FA on AWD was observed in southern China. FA supplementation successfully reduced the prevalence of AWD in northern China.