Oral clefts and life style factors — A case-cohort study based on prospective Danish data

Scientific opinion on the tolerable upper intake level for preformed vitamin A and β-carotene

Following two requests from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the revision of the tolerable upper intake level (UL) for preformed vitamin A and β-carotene. Systematic reviews of the literature were conducted for priority adverse health effects of excess vitamin A intake, namely teratogenicity, hepatotoxicity and endpoints related to bone health. Available data did not allow to address whether β-carotene could potentiate preformed vitamin A toxicity. Teratogenicity was selected as the critical effect on which to base the UL for preformed vitamin A. The Panel proposes to retain the UL for preformed vitamin A of 3000 μg RE/day for adults. This UL applies to men and women, including women of child-bearing age, pregnant and lactating women and post-menopausal women. This value was scaled down to other population groups using allometric scaling (body weight0.75), leading to ULs between 600 μg RE/day (infants 4-11 months) and 2600 μg RE/day (adolescents 15-17 years). Based on available intake data, European populations are unlikely to exceed the UL for preformed vitamin A if consumption of liver, offal and products thereof is limited to once per month or less. Women who are planning to become pregnant or who are pregnant are advised not to consume liver products. Lung cancer risk was selected as the critical effect of excess supplemental β-carotene. The available data were not sufficient and suitable to characterise a dose-response relationship and identify a reference point; therefore, no UL could be established. There is no indication that β-carotene intake from the background diet is associated with adverse health effects. Smokers should avoid consuming food supplements containing β-carotene. The use of supplemental β-carotene by the general population should be limited to the purpose of meeting vitamin A requirements.

An intercontinental comparison of the influence of smoking on the occurrence of nonsyndromic cleft lip and palate: a meta-analysis and systematic review

BACKGROUND

The influence of smoking on nonsyndromic clefts has been a topic of research for many years. However, few studies have investigated the effect of smoking on causing clefts in different gene pools.

METHODS

A meta-analysis was conducted of case-control studies related to smoking. Keywords such as "clefts," "cleft lip," "cleft palate," "orofacial cleft," and "smoking" were used to search the MEDLINE, Embase, and Cochrane databases.

RESULTS

In total, 51 articles were reviewed. The RevMan software was utilized for the analysis, and the Mantel-Haenszel method was employed to pool the odds ratios (ORs) and 95% confidence intervals. Although the overall OR, a measure of the association between exposure and outcome, was higher for smokers than for non-smokers, this association was significantly stronger in individuals from Asia and South America (1.73), and lowest in Europe (1.31). Among active and passive smokers in Asia, the OR was approximately 0.93, indicating an equivalent impact from both types of smoking.

CONCLUSION

This analysis indirectly suggests that restriction measures targeting both active and passive smoking are crucial in Asia.

Uncovering the Hidden Dangers and Molecular Mechanisms of Excess Folate: A Narrative Review

This review delves into the intricate relationship between excess folate (vitamin B9) intake, especially its synthetic form, namely, folic acid, and its implications on health and disease. While folate plays a pivotal role in the one-carbon cycle, which is essential for DNA synthesis, repair, and methylation, concerns arise about its excessive intake. The literature underscores potential deleterious effects, such as an increased risk of carcinogenesis; disruption in DNA methylation; and impacts on embryogenesis, pregnancy outcomes, neurodevelopment, and disease risk. Notably, these consequences stretch beyond the immediate effects, potentially influencing future generations through epigenetic reprogramming. The molecular mechanisms underlying these effects were examined, including altered one-carbon metabolism, the accumulation of unmetabolized folic acid, vitamin-B12-dependent mechanisms, altered methylation patterns, and interactions with critical receptors and signaling pathways. Furthermore, differences in the effects and mechanisms mediated by folic acid compared with natural folate are highlighted. Given the widespread folic acid supplementation, it is imperative to further research its optimal intake levels and the molecular pathways impacted by its excessive intake, ensuring the health and well-being of the global population.

Maternal consumption of caffeine and second-hand tobacco smoke as risk factors for the development of oral clefts

OBJECTIVE

The aim of this case-control study was to investigate environmental factors, such as caffeine, folic acid, nutritional iron supplementation, multivitamin complexes, alcohol, and tobacco (second-hand smoking), which have been described as risk factors for the development of oral clefts.

METHODS

This case-control study employed convenience sampling and included 409 mothers: 132 with children with oral clefts (cases) and 277 with children without oral clefts (controls). The age range of the children in both groups was 0 to 2 years. A questionnaire was administered to each mother to inquire about their habits and food consumption during the first trimester of pregnancy.

RESULTS

Folic acid supplementation was observed in 116 (87.8%) of the case group (p < 0.001) and 271 (97.8%) of the control group. Regarding the use of ferrous sulfate, 114 (86.3%) of the case group and 271 (97.8%) of the control group reported using it. In the case group, 84 (63.6%) mothers reported being exposed to second-hand smoke, and 5 (3.7%) reported alcohol consumption (p = 0.797). In terms of caffeine consumption, 127 mothers (95.4%) in the case group consumed it (p = 0.13), while 247 (88.8%) reported consumption in the control group.

CONCLUSIONS

The results suggest a direct relationship between secondhand smoke, alcohol consumption, and the lack of maternal supplementation with oral clefts.

Maternal dietary caffeine consumption and risk of birth defects in the National Birth Defects Prevention Study, 1997-2011

BACKGROUND

Caffeine consumption is common during pregnancy, but published associations with birth defects are mixed. We updated estimates of associations between prepregnancy caffeine consumption and 48 specific birth defects from the National Birth Defects Prevention Study (NBDPS) for deliveries from 1997 to 2011.

METHODS

NBDPS was a large population-based case-control study conducted in 10 U.S. states. We categorized self-reported total dietary caffeine consumption (mg/day) from coffee, tea, soda, and chocolate as: <10, 10 to <100, 100 to <200, 200 to <300, and ≥ 300. We used logistic regression to estimate adjusted odds ratios (aORs [95% confidence intervals]). Analyses for defects with ≥5 exposed case children were adjusted for maternal race/ethnicity, age at delivery, body mass index, early pregnancy cigarette smoking and alcohol use, and study site.

RESULTS

Our analysis included 30,285 case and 11,502 control children, with mothers of 52% and 54%, respectively, reporting consuming <100 mg caffeine, and 11% of mothers of both cases and controls reported consuming ≥300 mg per day. Low (10 to <100 mg/day) levels of prepregnancy caffeine consumption were associated with statistically significant increases in aORs (1.2-1.7) for 10 defects. Associations with high (≥300 mg/day) levels of caffeine were generally weaker, except for craniosynostosis and aortic stenosis (aORs = 1.3 [1.1-1.6], 1.6 [1.1-2.3]).

CONCLUSIONS

Given the large number of estimates generated, some of the statistically significant results may be due to chance and thus the weakly increased aORs should be interpreted cautiously. This study supports previous observations suggesting lack of evidence for meaningful associations between caffeine consumption and the studied birth defects.

Birth Defects Associated with Prenatal Alcohol Exposure-A Review

Since the recognition of fetal alcohol syndrome, alcohol has been accepted as a human teratogen. However, little is known about the relation between prenatal alcohol exposure and the spectrum of associated major birth defects. The objective of this review was to summarize data on the association of major congenital abnormalities and prenatal alcohol exposure. We included all major birth defects according to ICD-10 classification. We found that the strongest evidence to date lies in the research examining herniation (gastroschisis and omphalocele), oral clefts (cleft lip with or without palate and cleft palate) and cardiac defects. There is less consistent evidence supporting the association between prenatal alcohol exposure and anomalies of gastrointestinal system, diaphragmatic hernia, genitourinary system and neural tube defects. We found no material support for PAE and choanal atresia, biliary atresia or clubfoot.

Maternal Cigarette Smoking and Cleft Lip and Palate: A Systematic Review and Meta-Analysis

A systematic review and meta-analysis to determine the association between active maternal smoking and cleft lip and palate etiology.

Medline, Embase, Web of Science and the Cochrane Library from inception to November, 2020.

Observational studies of cigarette smoking habits in pregnant women. Outcomes included cleft lip and/or palate, cleft lip  ±  palate and cleft palate only.

Publication bias analyses were performed and the Newcastle Ottawa scales were used to assess study quality. Fixed or random effect models were used in the meta-analysis, dependent on risk of statistical heterogeneity.

Forty-five studies were eligible for inclusion of which 11 were cohort and 34 were case-control studies. Sixteen studies were of sufficient standard for inclusion in the meta-analysis. The summary odds ratio for the association between smoking and cleft lip and/or palate was 1.42 (95%CI 1.27-1.59) with a population attributable fraction of 4% (95%CI 3%-5%). There was limited evidence to show a dose-response effect of smoking.

This review reports a moderate association between maternal smoking and orofacial cleft but the overall quality of the conventional observational studies included was poor. There is a need for high quality and novel research strategies to further define the role of smoking in the etiology of cleft lip and palate.

Periconceptional use of vitamin A and the risk of giving birth to a child with nonsyndromic orofacial clefts-A meta-analysis

BACKGROUND

We conducted a meta-analysis of observational epidemiological studies to evaluate the association between periconceptional use of vitamin A and the risk of giving birth to a child with nonsyndromic orofacial clefts (NSOFCs).

METHODS

We carried out a systematic literature search of Embase, PubMed, Web of Science, Google Scholar, and OpenGrey from inception to June 30, 2021. Two reviewers independently evaluated the studies that met the inclusion criteria and filled out an abstraction form for each study. Study quality was assessed using the Newcastle-Ottawa Assessment Scale (NOS). Adjusted estimates were pooled with an inverse variance weighting using a random-effects model. Heterogeneity and publication bias were assessed using the Cochran's Q test and funnel plot, respectively.

RESULTS

A total of six case-control studies with moderate risk of bias were included. The pooled OR showed a 20% reduction in the risk of NSOFCs for periconceptional use of vitamin A which was not statistically significant (OR = .80; 95% CI .54-1.17, p = .25). For nonsyndromic cleft lip with or without cleft palate (NSCL/P), the studies were homogenous, and the pooled estimate showed a 13% risk reduction, which was significant (OR = .87; 95% CI .77-.99, p = .03). For nonsyndromic cleft palate only (NSCPO), the pooled estimate showed a 33% lower likelihood, which was not statistically significant (OR = .67; 95% CI .42-1.08, p = .10).

CONCLUSION

Our results suggest a possible protective effect for the periconceptional use of vitamin A on the risk of NSCL/P. This finding should be investigated further in prospective studies across multiple populations.

Single-nucleotide polymorphisms of methylenetetrahydrofolate reductase gene in a South Indian cohort with nonsyndromic cleft lip with or without palate

Objective:

Clefts of the lip, with or without cleft palate and cleft palate only, collectively called as orofacial clefts (OFCs) are one of the most common congenital malformations with varying degrees of penetrance and phenotype expressions. The aim of this study was to investigate the association between methylenetetrahydrofolate reductase (MTHFR) cytosine-to-thymine (c. 677 C>T), adenine-to-cytosine (c.1298 A>C) single- nucleotide polymorphisms (SNPs) and South Indian patients with the nonsyndromic cleft lip with or without palate (NSCL ± P).

Methods:

A cohort consisting of 25 cases of NSCL ± P and 18 controls from a South Indian cohort were included in this case–control study. Genetic analysis of c.677C>T and c.1298A C polymorphisms in the MTHFR gene was carried out using Sanger sequencing and analyzed from chromatogram profiles. Data interpretation was done using statistical software MedCalc Statistical Software version 16.2 and the Statistical Package for the Social Sciences (SPSS version 22.0).

Results:

DNA sequence analysis of the MTHFR gene revealed c. 677C>T and c. 1298A>C polymorphisms in 16% and 76% of NSCL ± P cases, respectively. Heterozygous variant in MTHFR c. 1298A>C polymorphism was found to be a significant risk factor (P = 0.0164) for NSCL ± P in South Indian ethnic population. c.677C>T polymorphism, in particular, was apparently dormant overall in the study population. These results offer certain novelty in terms of the distinctive pattern in SNPs of genotypes observed in the study.

Conclusion:

NSCL ± P is one of the most common and challenging congenital malformations with complex etiological basis. Common risk factors such as MTHFR SNPs, namely c.677C>T and c.1298A>C, are subjected to variations in terms of ethnic group, geographic region and micro/macro-environmental factors. Overall, our study has explored part of South Indian ethnic population and revealed a different and unique distribution of mutations in this sample population.

Caffeine exposure during pregnancy: Is it safe?

Numerous studies have examined the association between maternal caffeine consumption and infant and childhood health outcomes and the results have been inconsistent. The study of maternal caffeine intake and infant and childhood health outcomes is prone to methodologic challenges. In this review, we examine the existing evidence juxtaposed with the epidemiologic design challenges that color the interpretation of the study results presented. In light of methodologic/interpretation challenges, it seems reasonable to infer that exposure to low levels of caffeine is probably not associated with substantial infant and childhood adversities. However, more research is needed using well designed studies that address methodologic challenges.

Maternal intake of caffeinated products and birth defects: a systematic review and meta-analysis of observational studies

Caffeinated products are frequently consumed by women of childbearing age worldwide. It still unclear that whether maternal intake of caffeine associated with an increased risk of birth defects. We searched the databases of PubMed, Embase, the Cochrane Library, and Web of Science for eligible studies through July 2020. All studies examining the association between maternal consumption of caffeine or caffeinated products and birth defects were included. Twenty-nine studies were included in this meta-analysis. Among all the birth defects, maternal caffeine consumption was associated with a higher risk of cardiovascular defects, [odds ratio (OR) 1.17; 95% confidence interval (CI), 1.07-1.28], craniofacial defects (OR 1.09; 95% CI, 1.02-1.17), alimentary tract defects (OR 1.35; 95% CI, 1.16-1.56), and abdominal-wall defects and hernia (OR 1.13; 95% CI, 1.03-1.25). No association was found between maternal caffeine intake and musculoskeletal system defects, genitourinary system defects, nervous system defects, or chromosomal abnormalities. Meanwhile, all three of the caffeine consumption categories (low, moderate, and high) were associated with a higher risk of cardiovascular defects and alimentary tract defects.

Associations Between Disinfection By-Product Exposures and Craniofacial Birth Defects

OBJECTIVE

The aim of this study was to examine associations between craniofacial birth defects (CFDs) and disinfection by-product (DBP) exposures, including the sum of four trihalomethanes (THM4) and five haloacetic acids (HAA5) (ie, DBP9).

METHODS

We calculated first trimester adjusted odds ratios (aORs) for different DBPs in a matched case-control study of 366 CFD cases in Massachusetts towns with complete 1999 to 2004 THM and HAA data.

RESULTS

We detected elevated aORs for cleft palate with DBP9 (highest quintile aOR = 3.52; 95% CI: 1.07, 11.60), HAA5, trichloroacetic acid (TCAA), and dichloroacetic acid. We detected elevated aORs for eye defects with TCAA and chloroform.

CONCLUSION

This is the first epidemiological study of DBPs to examine eye and ear defects, as well as HAAs and CFDs. The associations for cleft palate and eye defects highlight the importance of examining specific defects and DBPs beyond THM4.

Psychological Well-being and Medical Guidance of Parents of Children With Cleft in Belgium During Feeding Problems of the Child: A Mixed Method Study

PURPOSE

Cleft is one of the most common anomalies affecting 1 in every 500-750 newborns. Depending on the type of cleft and its size, these children may experience feeding problems immediately after birth. Cleft has consequences for the child, as well as for the parents. The aim of this study was to gain a better understanding on the factors influencing the psychological well-being of the parents. Also, the experiences of parents of children with feeding problems and the received medical guidance were studied.

DESIGN AND METHODS

A mixed method convergent parallel design was used. In the quantitative study, a cross-sectional design was applied, in which parents completed 3 validated questionnaires about their psychological well-being. For the qualitative research a phenomenological design was used to conduct semi-structured interviews. Ninety parents agreed to join the quantitative study, of which 15 participated in the qualitative study as well.

RESULTS

The timing of the diagnosis revealed a significant difference in the depression and stress scores, while the number of children was significant for depression, anxiety, and stress. Other parental- and child-related factors did not cause a significant difference in psychological well-being. Different opinions about medical guidance and feeding problems came up during the interviews.

CONCLUSION

With these results, a recommendation toward future medical guidance can be given. The number of children and the timing of diagnosis were found to be significant variables determining the psychological well-being of the parents. All parents agreed on the need for a point of contact and an umbrella framework for a clearer guidance. Moreover, caregivers should have more knowledge about cleft and associated feeding problems.

Can contamination of the environment by dioxins cause craniofacial defects?

Cleft lip and cleft palate also known as orofacial cleft is a congenital malformation involving the partial or total lack of anatomical continuity of craniofacial tissue. The most common environmental factors that may cause orofacial clefts include pharmaceuticals, alcohol, addictive drugs, and tobacco smoke. Living in the area of industrial factories, garbage, ironworks, crematoria, wastewater treatment plants, and plastic waste landfills also has a significant impact on the development of the craniofacial defects. Some of the main factors causing the formation of congenital craniofacial defects are dioxins, of which emission to the environment is an important environmental and health problem. Dioxins are a diverse group of organic chemical compounds, derivatives of oxanthrene and fumarates, which are organoleptically imperceptible. Acting mainly through induction of inflammation, they influence a number of metabolic processes, including the process of bone mineralization and embryonic development. In this work, we highlight the problem of orofacial cleft including the impact of dioxin on development of this defect and the recommended prevention.

Prenatal alcohol exposure and offspring mental health: A systematic review

BACKGROUND

High levels of alcohol use in pregnancy have been shown to be associated with negative physical health consequences in offspring. However, the literature is less clear on the association of alcohol use in pregnancy and offspring mental health, specifically for low levels of prenatal alcohol exposure. We conducted a systematic review to evaluate studies examining this association.

METHODS

Studies were identified by searching PsycINFO, PubMed and Web of Science, and were included if they examined alcohol use during pregnancy as an exposure and offspring mental health at age 3 or older as an outcome. We excluded non-English language publications and studies of fetal alcohol syndrome.

RESULTS

Thirty-three studies were included and were categorized by mental health outcomes: anxiety/depression, emotional problems, total internalizing problems, total problem score, and conduct disorder. Over half of the analyses reported a positive association of prenatal alcohol exposure and offspring mental health problems.

CONCLUSIONS

Our review suggests that maternal alcohol use during pregnancy is associated with offspring mental health problems, even at low to moderate levels of alcohol use. Future investigation using methods that allow stronger causal inference is needed to further investigate if these associations shown are causal.

Cola Beverages: Clinical Uses versus Adverse Effects

Methods:

In this systematic review we tried to explore these new uses for practitioners and also reemphasize on the most evidence-based complications of cola consumption like bone loss and metabolic and cardiovascular adverse effects in cases of misuse and overuse from both clinical and nutritional points of view via searching the PubMed database.

Results:

We chose 145 journal articles from the most relevant ones plus 30 extra references and categorized their topics in two classes of medical uses and adverse effects.

Conclusion:

It could be stated that cola beverages have demonstrated interesting uses and benefits in medicine but their use should be regulated as strict as possible.

Maternal Folic Acid Supplementation and the Risk of Oral Clefts in Offspring

INTRODUCTION

There is controversial evidence from the literature regarding the protective effect of folic acid supplementation during pregnancy against orofacial clefts. The authors undertook this meta-analysis to assess whether folate supplementation during pregnancy can reduce the risk of nonsyndromic cleft lip with or without cleft palate (CL/P) and cleft palate only (CPO) in infants.

METHODS

Eligible articles were identified by searching databases, including PubMed, Medline, Scopus, ISI (Web of Knowledge) to September 2017. A meta-analysis was performed to evaluate the effects of maternal supplementation on oral clefts. Odds ratios (ORs) and 95% confidence intervals (CIs) were pooled using Stata software. Publication bias was assessed by the Begg and Egger test. (Registration ID: CRD42018083922) RESULTS:: Out of the 1630 articles found in the authors' initial literature searches, 6 cohort studies, and 31 case-control studies were included in the authors' final meta-analysis. The results of the main analysis revealed that maternal folate supplementation was associated with a modest but statically significant decreased risk of all cleft subtypes (OR = 0.69, 95% CI: 0.60, 0.78). Folic acid intake alone was inversely associated with CL/P (OR = 0.73, 95% CI: 0.62-0.85,) but to a lesser extent than CPO (OR = 0.75, 95% CI = 053-1.04). Multivitamin intake had a significant protective effect for CL/P (OR = 0.65 95% CI = 0.55-0.80) as well as CPO (OR = 0.69, 95% CI = 0.53-0.90).

CONCLUSIONS

Our results indicate that maternal supplementation in early pregnancy reduces the risk of nonsyndromic CL/P and CPO in infants. These data can serve to reassure women planning a pregnancy to consume multivitamins during the periconception period to protect against oral clefts.

Maternal underweight and obesity and risk of orofacial clefts in a large international consortium of population-based studies

Background

Evidence on association of maternal pre-pregnancy weight with risk of orofacial clefts is inconsistent.

Methods

Six large case-control studies of orofacial clefts from Northern Europe and the USA were included in analyses pooling individual-level data. Cases included 4943 mothers of children with orofacial clefts (cleft lip only: 1135, cleft palate with cleft lip: 2081, cleft palate only: 1727) and controls included 10 592 mothers of unaffected children. Association of orofacial cleft risk with pre-pregnancy maternal weight classified by level of body mass index (BMI, kg/m 2 ) was evaluated using logistic regression adjusting for multiple covariates.

Results

Cleft palate, both alone and with cleft lip (CP+/-CL), was associated with maternal class II+ pre-pregnancy obesity (≥ 35)compared with normal weight [adjusted odds ratio (aOR) = 1.36; 95% confidence interval (CI) = 1.16, 1.58]. CP+/-CL was marginally associated with maternal underweight (aOR = 1.16; 95% CI = 0.98, 1.36). Cleft lip alone was not associated with BMI.

Conclusions

In this largest population-based study to date, we found an increased risk of cleft palate, with or without cleft lip, in class II+ obese mothers compared with normal-weight mothers; underweight mothers may also have an increased risk, but this requires further study. These results also suggest that extremes of weight may have a specific effect on palatal development.

A Genome-Wide Search for Gene-Environment Effects in Isolated Cleft Lip with or without Cleft Palate Triads Points to an Interaction between Maternal Periconceptional Vitamin Use and Variants in ESRRG

Background: It is widely accepted that cleft lip with or without cleft palate (CL/P) results from the complex interplay between multiple genetic and environmental factors. However, a robust investigation of these gene-environment (GxE) interactions at a genome-wide level is still lacking for isolated CL/P. Materials and Methods: We used our R-package Haplin to perform a genome-wide search for GxE effects in isolated CL/P. From a previously published GWAS, genotypes and information on maternal periconceptional cigarette smoking, alcohol intake, and vitamin use were available on 1908 isolated CL/P triads of predominantly European or Asian ancestry. A GxE effect is present if the relative risk estimates for gene-effects in the offspring are different across exposure strata. We tested this using the relative risk ratio (RRR). Besides analyzing all ethnicities combined ("pooled analysis"), separate analyses were conducted on Europeans and Asians to investigate ethnicity-specific effects. To control for multiple testing, q-values were calculated from the p-values. Results: We identified significant GxVitamin interactions with three SNPs in "Estrogen-related receptor gamma" (ESRRG) in the pooled analysis. The RRRs (95% confidence intervals) were 0.56 (0.45-0.69) with rs1339221 (q = 0.011), 0.57 (0.46-0.70) with rs11117745 (q = 0.011), and 0.62 (0.50-0.76) with rs2099557 (q = 0.037). The associations were stronger when these SNPs were analyzed as haplotypes composed of two-SNP and three-SNP combinations. The strongest effect was with the "t-t-t" haplotype of the rs1339221-rs11117745-rs2099557 combination [RRR = 0.50 (0.40-0.64)], suggesting that the effects observed with the other SNP combinations, including those in the single-SNP analyses, were mainly driven by this haplotype. Although there were potential GxVitamin effects with rs17734557 and rs1316471 and GxAlcohol effects with rs9653456 and rs921876 in the European sample, respectively, none of the SNPs was located in or near genes with strong links to orofacial clefts. GxAlcohol and GxSmoke effects were not assessed in the Asian sample because of a lack of observations for these exposures. Discussion/Conclusion: We identified significant interactions between vitamin use and variants in ESRRG in the pooled analysis. These GxE effects are novel and warrant further investigations to elucidate their roles in orofacial clefting. If validated, they could provide prospects for exploring the impact of estrogens and vitamins on clefting, with potential translational applications.

Prevalence of non-syndromic orofacial clefts: based on 15,094,978 Chinese perinatal infants

Non-syndromic orofacial clefts (NSOFC), which include cleft lip and palate (CLP), cleft lip only (CLO), and cleft palate only (CPO), contains a range of disorders affecting the lips and oral cavity. No systematic review and meta-analysis has been carried out to synthesize the prevalence of NSOFC in Chinese perinatal infants. We aimed to quantify and understand the variation of prevalence national and regional levels. Four English databases and four Chinese databases were searched using a comprehensive search strategy from inception to April 2017. The random effect model was used for this meta-analysis. To determine the sources of heterogeneity, subgroup analyses and meta-regression were conducted based on different categories. The protocol has been pre-registered in the PROSPERO, number CRD42017062293. 110 studies, including 15,094,978 Chinese perinatal infants, were eligible for inclusion. The pooled prevalence rate for NSOFC was 1.67‰ (95% CI 1.53–1.82), varying with provinces. The pooled prevalence estimate was 0.56‰ (0.50–0.63) for CLO, 0.82‰ (0.73–0.90) for CLP, and 0.27‰ (0.24–0.30) for CPO. Significant associations were found between overall prevalence estimates and survey year and study region. The prevalence of NSOFC was severe in Chinese perinatal infants, varying with provinces. The results will serve as a baseline for future assessment of the overall effectiveness of NSOFC control, and will also support and inform health policy for planning and helping health debates.

Maternal exposures and risk of oral clefts in South Vietnam

BACKGROUND

Oral clefts are among the most common congenital anomalies. Most studies on risk factors of oral clefts have been carried out in developed countries. We investigated the associations between maternal exposures in the first trimester and oral clefts in South Vietnam.

METHODS

We conducted a hospital-based case-control study during October 2014-November 2015. Cases included 170 patients with nonsyndromic cleft lip with or without cleft palate and those with cleft palate only. Controls were 170 children without oral clefts, matched to each case by age and gender. Mothers were interviewed using structured questionnaire. We performed conditional logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Passive smoking was associated with increased risk of oral clefts in univariate analysis, but not in multivariable analysis (adjusted OR [aOR] = 1.68; 95% CI, 0.53-5.37). No association was observed between liver intake and oral clefts. Compared with nondrinkers, mothers who reported consumption of caffeine-containing beverages were more likely to have an infant with oral cleft (aOR = 5.89; 95% CI, 1.08-32.00). Periconceptional use of folic acid and multivitamins supplementation was associated with reduced risk of oral clefts (aOR = 0.01; 95% CI, 0.00-0.09 and aOR = 0.03; 95% CI, 0.01-0.13, respectively).

CONCLUSIONS

The results suggest no associations of maternal passive smoking or liver intake with oral clefts. Periconceptional use of folic acid or multivitamins may protect against oral clefts. Further studies are warranted to examine the roles of caffeine consumption in pregnant mothers on occurrence of oral clefts in offspring.

Low alcohol consumption and pregnancy and childhood outcomes: time to change guidelines indicating apparently 'safe' levels of alcohol during pregnancy? A systematic review and meta-analyses

OBJECTIVES

To determine the effects of low-to-moderate levels of maternal alcohol consumption in pregnancy on pregnancy and longer-term offspring outcomes.

SEARCH STRATEGY

Medline, Embase, Web of Science and Psychinfo from inception to 11 July 2016.

SELECTION CRITERIA

Prospective observational studies, negative control and quasiexperimental studies of pregnant women estimating effects of light drinking in pregnancy (≤32 g/week) versus abstaining. Pregnancy outcomes such as birth weight and features of fetal alcohol syndrome were examined.

DATA COLLECTION AND ANALYSIS

One reviewer extracted data and another checked extracted data. Random effects meta-analyses were performed where applicable, and a narrative summary of findings was carried out otherwise.

MAIN RESULTS

24 cohort and two quasiexperimental studies were included. With the exception of birth size and gestational age, there was insufficient data to meta-analyse or make robust conclusions. Odds of small for gestational age (SGA) and preterm birth were higher for babies whose mothers consumed up to 32 g/week versus none, but estimates for preterm birth were also compatible with no association: summary OR 1.08, 95% CI (1.02 to 1.14), I² 0%, (seven studies, all estimates were adjusted) OR 1.10, 95% CI (0.95 to 1.28), I² 60%, (nine studies, includes one unadjusted estimates), respectively. The earliest time points of exposure were used in the analysis.

CONCLUSION

Evidence of the effects of drinking ≤32 g/week in pregnancy is sparse. As there was some evidence that even light prenatal alcohol consumption is associated with being SGA and preterm delivery, guidance could advise abstention as a precautionary principle but should explain the paucity of evidence.

A Review of Systemic Corticosteroid Use in Pregnancy and the Risk of Select Pregnancy and Birth Outcomes

The evidence to date regarding corticosteroid exposure in pregnancy and select pregnancy and birth outcomes is limited and inconsistent. The authors provide a narrative review of published literature summarizing the findings for oral clefts, preterm birth, birth weight, preeclampsia, and gestational diabetes mellitus. Whenever possible, the results are limited to oral or systemic administration with a further focus on use in autoimmune disease. Although previous studies of corticosteroid exposure in pregnancy reported an increased risk of oral clefts in the offspring, more recent studies have not replicated these findings.

The impact of folic acid supplementation on gestational and long term health: Critical temporal windows, benefits and risks

Highlights

Associations between FA supplementation in pregnancy and effects on offspring's NTDs, allergy/respiratory problems, cancer and behaviour problems as been studied.There is growing concern about the effects of excessive FA supplementation, whether in terms of doses or times of exposure.FA supplementation in the periconceptional period is protective against NTDs while in later periods it could be deleterious.A daily dose of 0.4 mg FA in the periconceptional period seems to be effective and safe.

Abstract

Maternal folic acid (FA) supplementation is one of the most popular nutritional interventions during pregnancy for its protective effect against neural tube defects (NTDs).The purposes of this review are: (a) to gather the current evidence regarding supplementation of maternal diet with FA and (b) to problematize the available literature in terms of dosages, critical temporal windows, and its potential benefits and risks.The expression (pregnancy OR fetus OR offspring OR mother) AND ("folic acid" AND supplementation) was searched on PubMed database, filtering for articles published from 2005 to 2014. Publications referring to FA supplementation during the periconceptional period or pregnancy in which there was a conclusion about the effects of isolated FA supplementation on pregnant woman, pregnancy or offspring were included. Of the initial 1182 papers, 109 fulfilled the inclusion criteria.The majority of the publications reported FA supplementation outcomes on offspring's health, with emphasis in NTDs, allergy/respiratory problems, cancer and behaviour problems. Some inconsistency is observed on the impact of FA supplementation on different outcomes, except for NTDs. It is also visible an increased concern about the impact of excessive supplementation, either in terms of doses or exposure's duration.In conclusion, there is a growing interest in FA supplementation issues. The protective effect of FA supplementation over NTDs has been confirmed, being the periconceptional period a critical window, and it is frequently suggested that allergy/respiratory outcomes arise from (excessive) FA supplementation particularly later in pregnancy. Further research on critical doses and time of exposure should be conducted.

Interaction between smoking and body mass index and risk of oral clefts

PURPOSE

To examine maternal smoking and body mass index (BMI) interactions in contributing to risk of oral clefts.

METHODS

We studied 4935 cases and 10,557 controls from six population-based studies and estimated a pooled logistic regression of individual-level data, controlling for study fixed effects and individual-level risk factors.

RESULTS

We found a significant negative smoking-BMI interaction, with cleft risk with smoking generally declining with higher BMI. For all clefts combined, the odds ratio for smoking was 1.61 (95% confidence interval [CI]: 1.39-1.86) at BMI 17 (underweight), 1.47 (95% CI: 1.34-1.62) at BMI 22 (normal weight), 1.35 (95% CI: 1.22-1.48) at BMI 27 (overweight), 1.21 (95% CI: 1.04-1.41) at BMI 33 (obese), and 1.13 (95% CI: 0.92-1.38) at BMI 37 (very obese). A negative interaction was also observed for isolated clefts and across cleft types but was more pronounced for cleft lip only and cleft palate only.

CONCLUSIONS

Our findings suggest that the risk of oral clefts associated with maternal smoking is largest among underweight mothers, although the smoking-BMI interaction is strongest for cleft lip only and cleft palate only. BMI was not protective for the effects of smoking; a clinically relevant increase in smoking-related cleft risk was still present among heavier women.

Genetics and genomics etiology of nonsyndromic orofacial clefts

Orofacial clefts (OFC) are complex birth defects. Studies using contemporary genomic techniques, bioinformatics, and statistical analyses have led to appreciable advances in identifying the causes of syndromic forms of clefts. This commentary gives an overview of the important cleft gene discoveries found using various genomic methods and tools.

A discriminant analysis prediction model of non-syndromic cleft lip with or without cleft palate based on risk factors

BACKGROUND

A risk prediction model of non-syndromic cleft lip with or without cleft palate (NSCL/P) was established by a discriminant analysis to predict the individual risk of NSCL/P in pregnant women.

METHODS

A hospital-based case-control study was conducted with 113 cases of NSCL/P and 226 controls without NSCL/P. The cases and the controls were obtained from 52 birth defects' surveillance hospitals in Hunan Province, China. A questionnaire was administered in person to collect the variables relevant to NSCL/P by face to face interviews. Logistic regression models were used to analyze the influencing factors of NSCL/P, and a stepwise Fisher discriminant analysis was subsequently used to construct the prediction model.

RESULTS

In the univariate analysis, 13 influencing factors were related to NSCL/P, of which the following 8 influencing factors as predictors determined the discriminant prediction model: family income, maternal occupational hazards exposure, premarital medical examination, housing renovation, milk/soymilk intake in the first trimester of pregnancy, paternal occupational hazards exposure, paternal strong tea drinking, and family history of NSCL/P. The model had statistical significance (lambda = 0.772, chi-square = 86.044, df = 8, P < 0.001). Self-verification showed that 83.8 % of the participants were correctly predicted to be NSCL/P cases or controls with a sensitivity of 74.3 % and a specificity of 88.5 %. The area under the receiver operating characteristic curve (AUC) was 0.846.

CONCLUSIONS

The prediction model that was established using the risk factors of NSCL/P can be useful for predicting the risk of NSCL/P. Further research is needed to improve the model, and confirm the validity and reliability of the model.

Maternal active smoking and risk of oral clefts: a meta-analysis

OBJECTIVE

To assess the association between maternal active cigarette smoking and the risk of oral clefts in the offspring.

STUDY DESIGN

Oral clefts are divided into three subgroups: total clefts, cleft lip with or without cleft palate (CL ± P), and cleft palate only (CP). Data from studies on different levels of smoking were gathered to examine the dose-response effect.

RESULTS

The present meta-analysis included 29 case-control and cohort studies through Cochrane, PubMed, and Ovid Medline searches. A modest but statistically significant association was found between maternal active smoking and CL ± P (odds ratio [OR] 1.368; 95% confidence interval [CI] 1.259-1.486) as well as CP (OR 1.241; 95% CI 1.117-1.378). Half the studies showed positive dose-response effect for each subgroup (test for linear trend, P < .05).

CONCLUSIONS

There is a moderate risk for having a child with a CL ± P or CP in women who smoke during pregnancy. We could not confirm whether there was a positive dose-response effect between maternal smoking and clefts.

Maternal smoking during pregnancy and birth defects in children: a systematic review with meta-analysis

This systematic review aimed to investigate the association between maternal smoking during pregnancy and birth defects in children. We performed an electronic search of observational studies in the databases ovid MEDLINE (1950 to April 2010), LILACS and SciELO. We included 188 studies with a total of 13,564,914 participants (192,655 cases). Significant positive associations were found between maternal smoking and birth defects in the following body systems: cardiovascular (OR: 1.11; 95%CI: 1.03-1.19), digestive (OR: 1.18; 95%CI: 1.07-1.30), musculoskeletal (OR: 1.27; 95%CI: 1.16-1.39) and face and neck (OR: 1.28; 95%CI: 1.19-1.37). The strength of association between maternal smoking and birth defects measured by the OR (95%CI) is significantly related to the amount of cigarettes smoked daily (χ2 = 12.1; df = 2; p = 0.002). In conclusion, maternal smoking during pregnancy is associated with congenital malformations in children and this association is dose-dependent.

Epidemiology, Etiology, and Treatment of Isolated Cleft Palate

Isolated cleft palate (CPO) is the rarest form of oral clefting. The incidence of CPO varies substantially by geography from 1.3 to 25.3 per 10,000 live births, with the highest rates in British Columbia, Canada and the lowest rates in Nigeria, Africa. Stratified by ethnicity/race, the highest rates of CPO are observed in non-Hispanic Whites and the lowest in Africans; nevertheless, rates of CPO are consistently higher in females compared to males. Approximately fifty percent of cases born with cleft palate occur as part of a known genetic syndrome or with another malformation (e.g., congenital heart defects) and the other half occur as solitary defects, referred to often as non-syndromic clefts. The etiology of CPO is multifactorial involving genetic and environmental risk factors. Several animal models have yielded insight into the molecular pathways responsible for proper closure of the palate, including the BMP, TGF-β, and SHH signaling pathways. In terms of environmental exposures, only maternal tobacco smoke has been found to be strongly associated with CPO. Some studies have suggested that maternal glucocorticoid exposure may also be important. Clearly, there is a need for larger epidemiologic studies to further investigate both genetic and environmental risk factors and gene-environment interactions. In terms of treatment, there is a need for long-term comprehensive care including surgical, dental and speech pathology. Overall, five main themes emerge as critical in advancing research: (1) monitoring of the occurrence of CPO (capacity building); (2) detailed phenotyping of the severity (biology); (3) understanding of the genetic and environmental risk factors (primary prevention); (4) access to early detection and multidisciplinary treatment (clinical services); and (5) understanding predictors of recurrence and possible interventions among families with a child with CPO (secondary prevention).

Parental risk factors for oral clefts among Central Africans, Southeast Asians, and Central Americans

Background

Several lifestyle and environmental exposures have been suspected as risk factors for oral clefts, although few have been convincingly demonstrated. Studies across global diverse populations could offer additional insight given varying types and levels of exposures.

Methods

We performed an international case–control study in the Democratic Republic of the Congo (133 cases, 301 controls), Vietnam (75 cases, 158 controls), the Philippines (102 cases, 152 controls), and Honduras (120 cases, 143 controls). Mothers were recruited from hospitals and their exposures were collected from interviewer‐administered questionnaires. We used logistic regression modeling to estimate odds ratios (OR) and 95% confidence intervals (CI).

Results

Family history of clefts was strongly associated with increased risk (maternal: OR = 4.7; 95% CI, 3.0–7.2; paternal: OR = 10.5; 95% CI, 5.9–18.8; siblings: OR = 5.3; 95% CI, 1.4–19.9). Advanced maternal age (5 year OR = 1.2; 95% CI, 1.0–1.3), pregestational hypertension (OR = 2.6; 95% CI, 1.3–5.1), and gestational seizures (OR = 2.9; 95% CI, 1.1–7.4) were statistically significant risk factors. Lower maternal (secondary school OR = 1.6; 95% CI, 1.2–2.2; primary school OR = 2.4, 95% CI, 1.6–2.8) and paternal education (OR = 1.9; 95% CI, 1.4–2.5; and OR = 1.8; 95% CI, 1.1–2.9, respectively) and paternal tobacco smoking (OR = 1.5, 95% CI, 1.1–1.9) were associated with an increased risk. No other significant associations between maternal and paternal factors were found; some environmental factors including rural residency, indoor cooking with wood, chemicals and water source appeared to be associated with an increased risk in adjusted models.

Conclusion

Our study represents one of the first international studies investigating risk factors for clefts among multiethnic underserved populations. Our findings suggest a multifactorial etiology including both maternal and paternal factors. Birth Defects Research (Part A) 103:863–879, 2015. © 2015 The Authors Birth Defects Research Part A: Clinical and Molecular Teratology Published by Wiley Periodicals, Inc.

Long-term effects of oral clefts on health care utilization: a sibling comparison

Oral clefts are among the most common birth defects affecting thousands of newborns each year, but little is known about their potential long-term consequences. In this paper, we explore the impact of oral clefts on health care utilization over most of the lifespan. To account for time-invariant unobservable parental characteristics, we compare affected individuals with their own unaffected siblings. The analysis is based on unique data comprising the entire cohort of individuals born with oral clefts in Denmark tracked until adulthood in administrative register data. We find that children with oral clefts use more health services than their unaffected siblings. Additional results show that the effects are driven primarily by congenital malformation-related hospitalizations and intake of anti-infectives. Although the absolute differences in most health care utilization diminish over time, affected individuals have slightly higher utilization of some health care services in adulthood (particularly for diseases of the nervous and respiratory system). These results have important implications for affected individuals, their families, and their health professionals.

Risk factors involved in orofacial cleft predisposition - review

Clefts that occur in children are a special topic. Avoiding risk factors, and also an early diagnosis of cleft possibility can result in minimizing or avoiding them. If on the other hand when clefts occur they require a long-term, multistage specialized treatment. Etiology of clefts seems to be related to many factors. Factors such as genetic, environmental, geographic and even race factors are important. Identification of risk factors can lead to prevention and prophylactic behaviors in order to minimize its occurrence. Exposure to environmental factors at home and work that lead to cleft predisposition should not be disregarded. It seems that before planning a family it would be wise to consult with doctors of different specializations, especially in high-risk families with cleft history in order to analyze previous lifestyle. Clefts are very common in hereditary facial malformations and are causing a lot of other irregularities in the head and neck region. In this paper after a brief papers review authors present socio-geographic, environmental and also work place related factors that are influencing pregnant women condition and should be taken under serious consideration.

Use of corticosteroids in early pregnancy is not associated with risk of oral clefts and other congenital malformations in offspring

Corticosteroids are commonly used to treat inflammatory diseases. There is conflicting evidence regarding the association of corticosteroid use in pregnancy and congenital malformations in offspring. We conducted a prevalence study of 83,043 primiparous women who gave birth to a live-born singleton in northern Denmark, in 1999-2009. Through medical registries, we identified prescriptions for corticosteroids, congenital malformations, and covariates. Furthermore, we summarized the literature on this topic. Overall, 1449 women (1.7%) used inhaled or oral corticosteroids from 30 days before conception throughout the first trimester. Oral cleft in the offspring was recorded for 1 of the users (0.08%) and 145 of the nonusers (0.2%), prevalence odds ratio (OR) 0.47 [95% confidence interval (CI), 0.07-3.34]. The prevalence OR for congenital malformations overall was 1.02 (95% CI, 0.79-1.32). According to published studies, the use of corticosteroids in early pregnancy was associated with congenital malformations overall with relative estimates ranging from 0.8 (95% CI, 0.4-1.7) to 2.1 (95% CI, 0.5-9.6). For oral clefts, the ORs ranged from 0.6 (95% CI, 0.2-1.7) to 5.2 (95% CI, 1.5-17.1). We found no evidence of an association between use of corticosteroids in early pregnancy and risk of congenital malformations in offspring.

Maternal alcohol consumption during pregnancy and the risk of orofacial clefts in infants: a systematic review and meta-analysis

BACKGROUND

The teratogenic effects of maternal alcohol consumption during pregnancy include anomalies of craniofacial structures derived from the cranial neural crest cells. The presence of specific craniofacial anomalies contributes to the diagnosis of fetal alcohol spectrum disorders. Cleft lip and palate [orofacial clefts (OFCs)], also derived from the cranial neural crest cells, are common congenital anomalies, but their relationship with prenatal alcohol consumption is unknown.

METHODS

To evaluate the association between maternal consumption of alcohol during pregnancy and the occurrence of OFCs in infants, we conducted a systematic review and meta-analyses of published studies. We examined the associations between any alcohol consumption, binge level drinking, and heavy and moderate levels of consumption vs. no or low levels of consumption.

RESULTS

After screening 737 publications, we identified 33 studies (23 case-control and 10 cohort studies). There was considerable heterogeneity in individual study design, quality measures and study results. Findings from random effects meta-analyses suggest no relationship between prenatal alcohol consumption and the occurrence of OFCs {pooled odds ratios for any alcohol intake and binge level drinking respectively: cleft lip with or without cleft palate 1.00 [95% confidence interval (CI) 0.86, 1.16] from 18,349 participants in 13 studies, 1.04 [95% CI 0.87, 1.24] [8763 individuals, 4 studies]; cleft palate only 1.05 [95% CI 0.92, 1.21] [21,459 individuals, 17 studies], 0.94 [95% CI 0.74, 1.21] [7730 participants, 4 studies]}.

CONCLUSIONS

While we found no association between alcohol consumption during pregnancy and OFCs in infants, the influence of study design, particularly in relation to alcohol exposure measurement and OFC ascertainment cannot be ignored.

Prevalence and factors associated with congenital malformations in tirana, Albania, during 2011-2013

Aim:

Congenital Malformations (CMs) represent a challenge especially for developing countries. Data about CMs in Albania are rather scarce. In this context, our aim was to assess the prevalence and factors associated with CMs in Tirana, the capital of Albania.

Methods:

Information on all CMs at birth during 2011-2013 was retrieved from the National CM Surveillance System. For each CM case, three controls (babies born without CM) were retrieved as well. Overall, 831 cases and 2522 controls were included in this study. The prevalence was calculated using the total number of live births in Tirana during the same period. Binary logistic regression was used to determine the factors associated with CMs adjusting for a number of covariates.

Results:

The three-year prevalence of CMs was 23.41 per 1,000 live births. The most affected body systems were the musculoskeletal, cardiovascular and genital systems. CMs were more prevalent among male babies. Advanced mothers’ age, lower education, unemployment status and lower gestational age were all positively associated with increased likelihood of CMs.

Conclusions:

Socio-demographic factors of mothers are linked to CMs in Albania. Future surveys are needed in Albania in order to establish determinants of CMs at a national level.

Descriptive and risk factor analysis for choanal atresia: The National Birth Defects Prevention Study, 1997-2007

Choanal atresia causes serious posterior nasal obstruction. This defect is the leading cause of nasal surgery in newborns, although its etiology is largely unknown. Data from the National Birth Defects Prevention Study, a population-based case-control study, were used to examine associations between maternal self-reports of exposures and occurrence of choanal atresia in their offspring. Overall, 117 case and 8350 control mothers with deliveries from 1997 through 2007 provided telephone interview reports of pre-pregnancy (one year before conception) and periconceptional (one month before through three months after conception) exposures. The exposures analyzed were pre-pregnancy dietary intake, pre-pregnancy and periconceptional caffeine consumption, and periconceptional cigarette smoking, alcohol drinking, and medication use. Independent associations between each exposure and all choanal atresia cases combined (n = 117) and isolated choanal atresia cases (those without additional unrelated major defects; n = 61) were examined. Odds ratios (ORs), both unadjusted (uORs) and adjusted (aORs) for potential confounders, and 95% confidence intervals (CIs) were estimated using unconditional logistic regression analysis. For all choanal atresia cases combined, positive associations were observed with maternal pre-pregnancy intake in the highest quartile for vitamin B-12 (aOR = 1.9; CI = 1.1,3.1), zinc (aOR = 1.7; CI = 1.0,3.1), and niacin (aOR = 1.8; CI = 1.0,3.1), and intake in the lowest quartile for methionine (aOR = 1.6; CI = 1.0,2.6) and vitamin D (aOR = 1.6; CI = 1.0,2.4) compared to intake in the two intermediate quartiles combined. Further, a positive association was observed with periconceptional use of thyroid medications (uOR = 2.6; CI = 1.0,6.3) compared to no use of such medications. Among isolated choanal atresia cases, negative associations were observed for pantothenic acid (aOR = 0.4; CI = 0.2,0.9) and fat (aOR = 0.5; 95% CI = 0.2,1.0) intake in the lowest quartile compared to that in the intermediate quartiles, and positive associations were observed for periconceptional cigarette smoking (aOR = 2.3; CI = 1.1,4.7) compared to no smoking and pre-pregnancy daily coffee intake of 3 or more cups (aOR = 2.5; CI = 1.1,5.6) compared to intake of less than 1 cup per day. The positive association for periconceptional exposure to thyroid medications also persisted for isolated choanal atresia cases (uOR = 4.0; CI = 1.1,11.2). Because of the large number of associations tested, these findings may be due to chance. Alternatively, they may contribute new hypotheses regarding the etiology of choanal atresia; thus, requiring replication in additional studies.

Otorhinolaryngology/maxillofacial disorders

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Upper respiratory infections are ubiquitous

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Voice changes may herald laryngeal cancer

Vitamin B(12) metabolism during pregnancy and in embryonic mouse models

Vitamin B(12) (cobalamin, Cbl) is required for cellular metabolism. It is an essential coenzyme in mammals for two reactions: the conversion of homocysteine to methionine by the enzyme methionine synthase and the conversion of methylmalonyl-CoA to succinyl-CoA by the enzyme methylmalonyl-CoA mutase. Symptoms of Cbl deficiency are hematological, neurological and cognitive, including megaloblastic anaemia, tingling and numbness of the extremities, gait abnormalities, visual disturbances, memory loss and dementia. During pregnancy Cbl is essential, presumably because of its role in DNA synthesis and methionine synthesis; however, there are conflicting studies regarding an association between early pregnancy loss and Cbl deficiency. We here review the literature about the requirement for Cbl during pregnancy, and summarized what is known of the expression pattern and function of genes required for Cbl metabolism in embryonic mouse models.

[Orofacial closure defects: cleft lip and palate. A literature review]

Orofacial clefts are a common problem that can lead to significant healthcare use and costs, as well as suffering on the part of the affected individuals and families. There are several theories explaining their origin, but some of the findings are inconsistent. The most accepted theories involve a major genetic basis that could be modified by the presence of external agents. Understanding the underlying causes could help to prevent its occurrence, an area in which the family physician can play an important role.

Prevention of oro-facial clefts in developing world

Oro-facial cleft (OFC) remains a prominent health issue in developed and developing countries alike. It is the commonest craniofacial birth defect in humans. Mounting evidence suggest a polygenic, multifactorial and a list of epigenetic events. Primary prevention of OFC is based on recognition of the etiologic and risk factors. While a number of preventive strategies are in place for OFC in most developed countries of the world, the majority of developing countries are distant from achieving this goal for a number of reasons. Notable among these are a huge knowledge and practice gap in the field of genetics and dearth of accurate data. In addition, improper coordination and absenteeism from antenatal care contributed greatly to this set back. With ongoing efforts aimed at determining the genetics of nonsyndromic OFC in developing countries, researches directed at identifying environmental factors should equally be in place. Pending the outcome of these, implicated environmental and attitudinal risk factors in other populations could serve as preventive template in health education and interventions. Since risk factors vary between populations, definitive and effective preventive strategies and models would vary from place to place and from time to time. Frantic effort directed at identifying specific implicated risk factors in developing countries should include developing and keeping comprehensive national perinatal database and centralization of antenatal care protocol. Additionally, active health education at every level and a focus on developing manpower in the field of genetics should be in place. These would be designed and tailored toward identified, proven, and emerging risk factors.

Current concepts on the effect of environmental factors on cleft lip and palate

The aim of this study was to investigate the effect of environmental factors, such as tobacco, alcohol and folic acid intake, obesity, stressful events, low blood levels of zinc and fever during pregnancy, on the incidence of cleft lip and/or palate (CL±P). An electronic search was performed in the Cochrane Reviews, the ISI Web of Knowledge, PubMed and Scopus, along with a manual search to identify other relevant case-control and cohort studies. Quality assessments and an evaluation of publication bias were undertaken. Statistical heterogeneity was examined, and odds ratios (ORs) and 95% confidence intervals (CI) estimated using the random effects model. Of 372 articles initially retrieved, 28 studies were selected as eligible for meta-analysis. No evidence of publication bias was found using funnel plot analysis and the Egger linear regression method. Many studies were classified as low quality due to inadequate case-control data. On the basis of this research, maternal factors most associated with CL±P were: tobacco (OR 1.48), alcohol (OR 1.28), folic acid intake (OR 0.77), obesity (OR 1.26), stressful events (OR 1.41), low blood zinc levels (OR 1.82), and fever during pregnancy (OR 1.30). Folic acid intake by the mother reduced the risk of CL±P in offspring (OR 0.77).

Genetic and environmental risk factors for submucous cleft palate

A multifactorial aetiology with genetic and environmental factors is assumed for orofacial clefts. Submucous cleft palate (SMCP), a subgroup of cleft palates with insufficient median fusion of the muscles of the soft palate hidden under the mucosa, has a prevalence of 1:1,250-1:5,000. We described the prevalence of risk factors among 103 German patients with the subtype SMCP and genotyped 24 single nucleotide polymorphisms (SNPs) from 12 candidate genes for orofacial clefts. Analysis of risk factors yielded a positive history for maternal cigarette smoking during pregnancy in 25.2% of the patients, and this was significantly more frequent than in the normal population. The group of patients differed in allele frequencies at SNP rs3917192 of the gene TGFB3 (nominal P = 0.053) and at SNP rs5752638 of the gene MN1 (nominal P = 0.075) compared with 279 control individuals. Our results indicate a potential role of maternal smoking during pregnancy for the formation of SMCP. The analysis of genetic variants hints at the contribution of TGFB3 and MN1 in the aetiology of SMCPs.

Comparable levels of folate-induced aneusomy in B-lymphoblasts from oral-cleft patients and controls

BACKGROUND

Peri-conceptional use of folic acid contributes to protection against congenital malformations, such as neural tube defects and cleft lip with or without cleft palate (CL/P). Previous studies showed that low folate levels cause DNA damage, leading to chromosomal instability and aneusomy. This study seeks to confirm this finding and investigates whether the in vitro sensitivity towards aneusomy of chromosome 17 and 21 in the folate-deficient state differs between CL/P patients and controls.

METHODS

Epstein-Barr virus-immortalized B-lymphoblasts derived from 15 CL/P children and 15 controls, were cultured in medium with high and low concentrations - approximately 40nM and 5nM - of 5-methyltetrahydrofolate, respectively. Fluorescence in situ hybridization was used to detect specific fluorescence signals for chromosomes 17 and 21.

RESULTS

A significant increase in aneusomy of chromosomes 17 (2.3% vs 7.6%; p ≤ 0.001) and 21 (2.5% vs 7.0%; p ≤ 0.001) was observed after 10 days of culturing in low folate. These results were comparable in cell lines from patients and controls. Interestingly, for chromosome 17 the folate deficiency mainly resulted in an increase of monosomy (6%, p ≤ 0.001), while for chromosome 21 the increase of trisomy was larger (4.9%, p ≤ 0.001).

CONCLUSIONS

These data suggest that folate deficiency is a significant risk factor in the development of aneusomy and may affect the distribution of chromosomes during cell division. The comparable aneusomy frequencies in CL/P and in controls suggest that other folate-related processes are involved in the pathogenesis of CL/P, and additional investigations are needed to identify the causal mechanisms.