Can folic acid protect against congenital heart defects in Down syndrome?

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.

Maternal Risk Factors Triggering Congenital Heart Defects in Down Syndrome: A Case-Control Study

OBJECTIVES

Maternal MTHFR and MTRR polymorphisms as a risk of CHD in DS fetus were studied along with maternal folic acid supplementation, which could influence the folate metabolism along with other risk factors.

MATERIAL AND METHODS

A case-control study comprising of mothers of DS with and without CHD along with controls were recruited from a tertiary care center since 2018-2019. Genomic DNA was isolated followed by PCR-RFLP.

RESULTS

Mothers with age ≥35 years and having history of miscarriages have a higher risk of giving birth to DS with CHD (n = 35% and 42%, respectively). Mothers who carried the MTHFR 677CT/TT and MTRR 524CT/TT genotypes combination in the folic acid nonusers group during pregnancies had six-fold (OR = 6.909, p-value = 0.027; 95% CI-1.23 ± 38.51) and four-fold (OR = 4.75, p-value = 0.040; 95% CI-1.067 ± 21.44) increased odds of having a DS child with CHD, respectively, as compared to folic acid users.

CONCLUSION

Maternal age, folic acid supplementation, and previous history of miscarriages is involved in the etiology of CHD in DS fetus in Indian population. Maternal MTHFR and MTRR polymorphisms are also involved in the occurrence of CHD and DS in Indian population when controlling for periconceptional folic acid supplementation.

LIMITATIONS

Single-Centered Study.

Maternal risk factors for congenital heart defects in infants with Down syndrome from Western Mexico

Atrioventricular septal defects (AVSDs) have been identified as intriguingly infrequent among Hispanics with Down syndrome (DS) born in the United States. The aim of this study was to evaluate the effect of possible maternal risk factors in the presence of congenital heart defects (CHDs) in Mexican infants with DS. A total of 231 live birth infants born with DS during 2009-2018 at the "Dr. Juan I. Menchaca" Civil Hospital of Guadalajara (Guadalajara, Mexico) were ascertained in a case-control study. Patients with DS with any major CHD were included as cases and those without major CHD as controls. Potential risk factors were analyzed using logistic regression. Of eligible infants with DS, 100 (43.3%) had ≥1 major CHDs (cases) and were compared with a control group of 131 infants (56.7%) with DS without CHDs. Prevalent CHDs were ostium secundum atrial septal defects (ASDs) (46.9%), ventricular septal defects (27.3%), and AVSDs (14%). Lack of folic acid supplementation before pregnancy had a significant risk for CHDs in infants with DS (adjusted odds ratio [aORs] = 2.9 (95% confidence interval [95% CI]: 1.0-8.6) and in the analysis by subtype of CHDs, also, for the occurrence of ASDs (aOR = 11.5, 95% CI: 1.4-94.4). Almost half of the infants with DS in our sample had CHDs, being ASD the commonest subtype and AVSD the rarest. Our ethnic background alone or in concomitance with observed nutritional disadvantages seems to contribute differences in CHD subtype rates in our DS patients.

Prevalence of congenital heart diseases in children with Down syndrome in Mansoura, Egypt: a retrospective descriptive study

BACKGROUND

The pattern and risk factors for congenital heart diseases (CHD) in children with Down syndrome (DS) vary over time.

OBJECTIVES

To update knowledge of the prevalence, types, trends and associated factors for CHD in children with DS in the Egyptian Delta.

DESIGN

A retrospective hospital record-based descriptive study.

SETTING

A tertiary care center in Mansoura, Egypt during a period of 14 years from 2003 up to 2016.

PATIENTS AND METHODS

We studied children with genetically proven DS. Relevant sociodemographic factors, medical history, clinical examination, karyotype and echocardiographic data were statistically analyzed.

MAIN OUTCOME MEASURES

Prevalence, types and risk factors of CHD in DS.

RESULTS

The prevalence of overall, isolated and multiple CHD in 1720 children with DS were 36.9%, 29% and 8%, respectively. Isolated defects accounted for 78.4% of all CHD. Ventricular septal defect, atrioventricular septal defect and atrial septal defect were the most frequent isolated defects. There was a downward trend in the prevalence of overall CHD (from 56.2% to 25.0%) and isolated CHD (from 56.2% to 19.8%). The logistic regression model predicted 65.7% of CHD and revealed that passive maternal smoking, lack of folic acid/multivitamin supplementation and parental consanguinity were the independent predictors of CHD in children with DS with adjusted odds ratios of 1.9, 1.8 and 1.9, respectively.

CONCLUSION

More than one-third of children with DS have CHD with ventricular septal defect, which is the most common. Avoidance of passive maternal smoking and consanguineous marriage together with maternal folic acid supplementation could contribute to further reduction of CHD in children with DS.

LIMITATIONS

Single-center study and retrospective.

The Complex Genetic Basis of Congenital Heart Defects

Twenty years ago, chromosomal abnormalities were the only identifiable genetic causes of a small fraction of congenital heart defects (CHD). Today, a de novo or inherited genetic abnormality can be identified as pathogenic in one-third of cases. We refer to them here as monogenic causes, insofar as the genetic abnormality has a readily detectable, large effect. What explains the other two-thirds? This review considers a complex genetic basis. That is, a combination of genetic mutations or variants that individually may have little or no detectable effect contribute to the pathogenesis of a heart defect. Genes in the embryo that act directly in cardiac developmental pathways have received the most attention, but genes in the mother that establish the gestational milieu via pathways related to metabolism and aging also have an effect. A growing body of evidence highlights the pathogenic significance of genetic interactions in the embryo and maternal effects that have a genetic basis. The investigation of CHD as guided by a complex genetic model could help estimate risk more precisely and logically lead to a means of prevention.

A Meta-Analysis of the Relationship Between Maternal Folic Acid Supplementation and the Risk of Congenital Heart Defects

Controversial opinions exist with respect to the relationship between maternal folic acid (FA) supplementation and birth prevalence of congenital heart defects (CHDs).Eligible articles were retrieved by searching databases, including PubMed, Cochrane library, EMBASE, CNKI, and WanFang up to September 2015. A meta-analysis was performed to evaluate the effects of FA on CHDs. Odds ratios (ORs) and 95% confidence interval (CIs) were merged using STATA 12.0. Meta-regression analysis was used to explore the possible sources of heterogeneity. Subgroup analysis according to the selected sources was also performed. Publication bias was assessed by Egger's test.Twenty studies were included in the meta-analysis. The overall analysis showed that FA supplementation was significantly associated with decreased risk of CHDs. The meta-regression analysis showed that geographical area could be an important source of heterogeneity. The subgroup analysis based on the geographical area revealed that FA supplementation during pregnancy was a protective factor against CHDs in Chinese and European patients, but not in American patients. Subgroup analysis according to literature quality also displayed positive associations between FA supplementation and the decreased risk of CHDs of China.FA supplementation during pregnancy significantly decreases the risk of CHDs in newborns in China and Europe.

Lack of maternal folic acid supplementation is associated with heart defects in Down syndrome: a report from the National Down Syndrome Project

BACKGROUND

Maternal folic acid supplementation has been associated with a reduced risk for neural tube defects and may be associated with a reduced risk for congenital heart defects and other birth defects. Individuals with Down syndrome are at high risk for congenital heart defects and have been shown to have abnormal folate metabolism.

METHODS

As part of the population-based case-control National Down Syndrome Project, 1011 mothers of infants with Down syndrome reported their use of supplements containing folic acid. These data were used to determine whether a lack of periconceptional maternal folic acid supplementation is associated with congenital heart defects in Down syndrome. We used logistic regression to test the relationship between maternal folic acid supplementation and the frequency of specific heart defects correcting for maternal race or ethnicity, proband sex, maternal use of alcohol and cigarettes, and maternal age at conception.

RESULTS

Lack of maternal folic acid supplementation was more frequent among infants with Down syndrome and atrioventricular septal defects (odds ratio [OR], 1.69; 95% confidence interval [CI], 1.08-2.63; p = 0.011) or atrial septal defects (OR, 1.69; 95% CI, 1.11-2.58; p = 0.007) than among infants with Down syndrome and no heart defect. Preliminary evidence suggests that the patterns of association differ by race or ethnicity and sex of the proband. There was no statistically significant association with ventricular septal defects (OR, 1.26; 95% CI, 0.85-1.87; p = 0.124).

CONCLUSIONS

Our results suggest that lack of maternal folic acid supplementation is associated with septal defects in infants with Down syndrome. Birth Defects Research (Part A), 2011. © 2011 Wiley-Liss, Inc.

MTHFR C677T and A1298C polymorphisms as a risk factor for congenital heart defects in Down syndrome

BACKGROUND

Congenital heart defects (CHD) are present in most, but not all, cases of Down syndrome (DS). The presence of methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms has been reported as a risk factor for CHD in DS. The aims of the present study were to assess (i) the frequency of MTHFR C677T and A1298C polymorphisms in DS individuals in the Croatian population; (ii) the relationship between the two maternal MTHFR polymorphisms and CHD-affected DS children; and (iii) the transmission frequencies of the variant alleles of the two MTHFR polymorphisms in CHD-affected DS.

METHODS

The study population included 112 DS subjects and 221 controls. CHD were present in 48% of the DS subjects (54/112). The mothers of 107 DS individuals were available for the study; none was a periconceptional folic acid user. Allele transmission was analyzed in 34 complete parent-offspring triads.

RESULTS

The frequencies of the allele, individual, and combined genotypes of MTHFR C677T and A1298C in DS subjects were not statistically different compared to the normal healthy Croatian controls. The maternal MTHFR polymorphisms were not found to be a risk factor for DS-related CHD. The allele transmission of the two MTHFR polymorphisms showed no deviations from random segregation.

CONCLUSIONS

Because the fetus is lost in a great proportion of trisomy 21 pregnancies, both maternal and fetal, not only live-born MTHFR C677T and A1298C, as well as maternal nutrition and lifestyle during pregnancy, should be analyzed to asses the impact on CHD in DS.

Evaluation of C677T and A1298C polymorphisms of the MTHFR gene as maternal risk factors for Down syndrome and congenital heart defects

Abnormal folate/homocysteine metabolism due to polymorphisms in genes involved in this pathway has been implicated as an etiologic factor in Down syndrome (DS). This case-control study aimed to evaluate the effect of maternal C677T and A1298C polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) as risk factors for the development of DS and congenital heart defects (CHD). The distribution of these genotypic variants was similar between mothers of children with DS (n = 239) and control mothers of normal children (n = 197), but the combined genotypes 677CT or TT and 1298AA increased the risk of having offspring with DS (OR = 1.99; 95% CI 1.11-3.55). The presence of the 677T allele in case mothers resulted in a 2.07-fold higher odds of CHD in the offspring (P < 0.01). Among the 57 mothers of CHD-affected children with DS who carried the MTHFR 677CT or TT genotypes and did not have periconceptional folic acid intake, we observed a 2.26-fold increased odds (95% CI 1.25-4.09) of having any CHD-affected child with DS. Our results show that MTHFR genetic polymorphisms may be involved in the etiology of DS in our population when controlling for age. We noted a borderline significant association for the C677T polymorphism (P = 0.05). Maternal 677T allele may be associated with an increased occurrence of CHD in children with DS and we anticipate that women who carry this polymorphism would benefit from periconceptional folic acid supplementation. (c) 2009 Wiley-Liss, Inc.

Effect of interpregnancy interval on adverse perinatal outcomes--a national study

BACKGROUND

The interpregnancy interval (IPI) has been reported to influence the outcome of pregnancy and birth. We performed a national study in Israel to determine the impact of IPI on multiple adverse perinatal outcomes.

STUDY DESIGN

This longitudinal cohort study used birth certificates of siblings born to the same biological mother, with at least one previous birth and a subsequent singleton pregnancy. Adverse pregnancy outcomes included preterm delivery, very preterm birth, small for gestational age (SGA), very SGA (VSGA), early neonatal death and major congenital malformations. Multivariate logistic regression was performed for each outcome.

RESULTS

The study included 440,838 of a total of 846,845 reported live births in Israel over 5 years; excluded were primiparas (32%), multifetal births (4.9%) and those with incomplete data (10.9%). For IPIs shorter than 6 months, there were significantly increased risks for preterm birth (OR=1.23), SGA (OR=1.14), VSGA (OR=1.15), early neonatal death (OR=1.62) and congenital malformations (OR=1.14). Intervals of 60 months or longer had higher risks for preterm birth (OR=1.39) and VSGA (OR=1.16).

CONCLUSION

Optimal IPI recommendation of >11 months is an accessible and low-cost means to improve multiple adverse perinatal outcomes.