Smoking and orofacial clefts: a United Kingdom-based case-control study

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.

Epidemiology of Nonsyndromic, Orofacial Clefts in Texas: Differences by Cleft Type and Presence of Additional Defects

To describe the current epidemiology of nonsyndromic cleft palate alone (CP) and cleft lip with or without cleft palate (CL ± P) in Texas and examine differences in the characteristics of infants with CP and CL ± P based on the presence/absence of additional defects.

We used data from the Texas Birth Defects Registry, a statewide active birth defect surveillance system, from 1815 cases with CP and 5066 with CL ± P, without a syndrome diagnosis (1999-2014 deliveries). All live births in Texas were used for comparison. Poisson regression was used to calculate crude and adjusted prevalence ratios (aPR) for each characteristic, separately for each cleft subphenotype.

The prevalence of CL ± P and CP in our study was estimated as 8.3 and 3.0 per 10 000 live births, respectively. After adjusting for several characteristics, several factors were associated with CL ± P, CP, or both, including infant sex and maternal race/ethnicity, age, smoking, and diabetes. There were several differences between infants with isolated versus nonisolated clefts. For example, maternal prepregnancy diabetes was associated with an increased prevalence of CL ± P (aPR 7.91, 95% confidence interval [CI]: 5.53, 11.30) and CP (aPR 3.24, 95% CI: 1.43, 7.36), but only when additional defects were present.

Findings from this study provide a contemporary description of the distribution of orofacial clefts in Texas accounting for differences between isolated and nonisolated clefts. They may contribute to increasing our understanding of the etiology of CP and CL ± P.

Environmental tobacco smoke exposure and non-syndromic orofacial cleft: Systematic review and meta-analysis

INTRODUCTION

Environmental tobacco smoke (ETS) is associated with several congenital anomalies, including non-syndromic orofacial clefts (NSOFCs). This systematic review aimed to update the literature on the association between ETS and NSOFCs.

METHODS

Four databases were searched up to March 2022, and studies that evaluated the association between ETS and NSOFCs were selected. Two authors selected the studies, extracted the data, and evaluated the risk of bias. Comparing the association of maternal exposure to ETS and active parental smoking with NSOFCs allowed for the creation of pooled effect estimates for the included studies.

RESULTS

Twenty-six studies were deemed eligible for this review, of which 14 were reported in a previous systematic review. Twenty five were case-control studies, and one was a cohort study. In total, these studies included 2142 NSOFC cases compared to 118129 controls. All meta-analyses showed an association between ETS and the risk of having a child with NSOFC, based on the cleft phenotype, risk of bias, and year of publication, with a pooled increased odds ratio of 1.80 (95% CI: 1.51-2.15). These studies had a marked heterogeneity, which decreased upon subgrouping based on the recent year of publication and the risk of bias.

CONCLUSIONS

ETS exposure was associated with more than a 1.5-fold increase in the risk of having a child with NSOFC, showing a higher odds ratio than paternal and maternal active smoking.

TRIAL REGISTRATION

The study is registered on the International Prospective Register of Systematic Reviews database # CRD42021272909.

Maternal cigarette smoking before or during pregnancy increases the risk of birth congenital anomalies: a population-based retrospective cohort study of 12 million mother-infant pairs

BACKGROUND

The associations of maternal cigarette smoking with congenital anomalies in offspring have been inconsistent. This study aimed to clarify the associations of the timing and intensity of maternal cigarette smoking with 12 subtypes of birth congenital anomalies based on a nationwide large birth cohort in the USA.

METHODS

We used nationwide birth certificate data from the US National Vital Statistics System during 2016-2019. Women reported the average daily number of cigarettes they consumed 3 months before pregnancy and in each subsequent trimester during pregnancy. Twelve subtypes of congenital anomalies were identified in medical records. Poisson regression analysis was used to estimate the risk ratios (RRs) with 95% confidence intervals (CIs) for 12 subtypes of congenital anomalies associated with the timing (i.e., before pregnancy, and during three different trimesters of pregnancy) and intensity (i.e., number of cigarettes consumed per day) of maternal cigarette smoking.

RESULTS

Among the 12,144,972 women included, 9.3% smoked before pregnancy and 7.0%, 6.0%, and 5.7% in the first, second, and third trimester, respectively. Maternal smoking before or during pregnancy significantly increased the risk of six subtypes of birth congenital anomalies (i.e., congenital diaphragmatic hernia, gastroschisis, limb reduction defect, cleft lip with or without cleft palate, cleft palate alone, and hypospadias), even as low as 1-5 cigarettes per day. The adjusted RRs (95% CIs) for overall birth congenital anomalies (defined as having any one of the congenital malformations above significantly associated with maternal cigarette smoking) among women who smoked 1-5, 6-10, and ≥ 11 cigarettes per day before pregnancy were 1.31 (1.22-1.41), 1.25 (1.17-1.33), and 1.35 (1.28-1.43), respectively. Corresponding values were 1.23 (1.14-1.33), 1.33 (1.24-1.42), 1.33 (1.23-1.43), respectively, for women who smoked cigarettes in the first trimester; 1.32 (1.21-1.44), 1.36 (1.26-1.47), and 1.38 (1.23-1.54), respectively, for women who smoked cigarettes in the second trimester; and 1.33 (1.22-1.44), 1.35 (1.24-1.47), and 1.35 (1.19-1.52), respectively, for women who smoked cigarettes in the third trimester. Compared with women who kept smoking before and throughout pregnancy, women who never smoked had significantly lower risk of congenital anomalies (RR 0.77, 95% CI 0.73-0.81), but women who smoked before pregnancy and quitted during each trimester of pregnancy had no reduced risk (all P > 0.05).

CONCLUSIONS

Maternal smoking before or during pregnancy increased the risk of several birth congenital anomalies, even as low as 1-5 cigarettes per day. Maternal smokers who stopped smoking in the subsequent trimesters of pregnancy were still at an increased risk of birth congenital anomalies. Our findings highlighted that smoking cessation interventions should be implemented before pregnancy.

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

Objectives

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

Data sources

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

Study selection

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

Data analysis

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.

Results

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.

Conclusions

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.

Congenital anomalies among newborn babies in Felege-Hiwot Comprehensive Specialized Referral Hospital, Bahir Dar, Ethiopia

Congenital anomaly is a structural or functional defect which could occur in any organ system. The aim of this study was to determine the prevalence and associated factors of congenital anomalies among newborn babies delivered at Felege-Hiwot Comprehensive Specialized Referral Hospital, Bahir Dar, Ethiopia. A cross-sectional study design was used to review medical records/charts of 11,177 new born babies born at the delivery ward of Felege-Hiwot Comprehensive Specialized Referral Hospital, Ethiopia. The data were collected using an abstraction form. A bivariate analysis was done to assess factors associated with congenital anomalies. Variables whose p-value < 0.2 were included in the multivariable analysis to identify the effects of confounders. P-values < 0.05 were considered statistically significant. A total of 11,177 newborn babies and their mothers were included in the study and the proportion of congenital anomalies was found to be 0.62%. The most (46.4%) prevalent congenital anomaly was neural tube defects. Newborn birth weight < 1.25 kg [AOR, 32.6, 95% CI 11.9-89.0], and newborn weight < 2.5 kg [AOR, 2.67, 95% CI 1.54-4.65], antenatal visits [AOR, 4.0, 95% CI 2.39-6.69] and urban residence [AOR, 2.1, 95% CI 1.28-3.55] were statistically significant factors. In conclusion, neural tube defects were anomalies prevalent in this study. Antenatal visits, birth weight and residence were factors associated with congenital anomalies.

Risk factors associated with congenital anomalies among newborns in southwestern Ethiopia: A case-control study

INTRODUCTION

Human embryo is well protected in the uterus by the embryonic membrane, although teratogens may cause developmental disruptions after maternal exposure to them during early pregnancy. Most of the risk factors contributing to the development of congenital anomalies are uncertain; however, genetic factors, environmental factors and multifactorial inheritance are found to be risk factors. Regardless of their clinical importance, there are little/no studies conducted directly related to predisposing risk factors in southwestern Ethiopia.

OBJECTIVE

The study aimed to determine the associated risk factors with congenital anomalies among newborns in southwestern Ethiopia.

METHODS

Case-control study was conducted on newborns and their mothers in six purposively selected hospitals in southwestern Ethiopia from May 2016 to May 2018. Data was collected after evaluation of the neonates for the presence of congenital anomalies using the standard pretested checklist. The data was analyzed using SPSS version 25.0. P <0.01 was set as statistically significant.

RESULTS

Risk factors such as unidentified medicinal usage in the first three months of pregnancy (AOR = 3.435; 99% CI: 2.012-5.863), exposure to pesticide (AOR = 3.926; 99% CI: 1.266-12.176), passive smoking (AOR = 4.104; 99% CI: 1.892-8.901), surface water as sources of drinking (AOR = 2.073; 99% CI: 1.221-3.519), folic acid supplementation during the early pregnancy (AOR = 0.428; 99% CI: 0.247-0.740) were significantly associated with the congenital anomalies.

CONCLUSIONS

In this study, risk factors such as passive smoking, exposure to pesticides, chemicals and use of surface water as a source of drinking during early pregnancy had a significant association with congenital anomalies. There is a need to continuously provide health information for the community on how to prevent and control predisposing risk factors.

Sociodemographic Predictors of Patient Age at Time of Cleft Lip and Palate Repair

Objective:

To identify the impact of sociodemographic and health variables on the age at which patients undergo cleft lip repair, cleft palate repair, and primary speech evaluation.

Design:

A retrospective, noninterventional quality assessment, and quality improvement study was designed.

Setting:

This institutional study was performed at Michigan Medicine in Ann Arbor, MI.

Patients:

All patients born between 2011 and 2014 who received surgical cleft repair, excluded those who were adopted (n = 165).

Main Outcome Measure:

The age at which patients undergo cleft lip repair, cleft palate repair, and primary speech evaluation.

Results:

Cleft lip repair was performed significantly later for patients identifying as Asian (18 weeks, P = .01), patients with Child Protective Services contact (19 weeks, P = .01), patients with a significant comorbidity (14 weeks, P = .02), and patients who underwent preliminary lip adhesion surgery (19 weeks, P < .01). Cleft palate repair was performed significantly later for patients identifying racially as Asian (19 weeks, P = .03) and other (22 weeks, P = .03). Preliminary speech and language evaluation were performed significantly later for patients identifying as black (55 weeks, P = .03) and patients diagnosed with an isolated cleft lip (71 weeks, P < .01).

Conclusions:

Timing of cleft lip, cleft palate repair, and primary speech and language evaluation are subject to variation which may be predicted by clinically accessible factors. By identifying race, Child Protective Services contact, and care variables as significant predictors of increased patient age at time of intervention, multidisciplinary cleft care teams can proactively allocate patient support resources.

Six2 regulates Pax9 expression, palatogenesis and craniofacial bone formation

In this study, we investigated the role of the transcription factor Six2 in palate development. Six2 was selected using the SysFACE tool to predict genes from the 2p21 locus, a region associated with clefting in humans by GWAS, that are likely to be involved in palatogenesis. We functionally validated the predicted role of Six2 in palatogenesis by showing that 22% of Six2 null embryos develop cleft palate. Six2 contributes to palatogenesis by promoting mesenchymal cell proliferation and regulating bone formation. The clefting phenotype in Six2^-/- embryos is similar to Pax9 null embryos, so we examined the functional relationship of these two genes. Mechanistically, SIX2 binds to a PAX9 5' upstream regulatory element and activates PAX9 expression. In addition, we identified a human SIX2 coding variant (p.Gly264Glu) in a proband with cleft palate. We show this missense mutation affects the stability of the SIX2 protein and leads to decreased PAX9 expression. The low penetrance of clefting in the Six2 null mouse combined with the mutation in one patient with cleft palate underscores the potential combinatorial interactions of other genes in clefting. Our study demonstrates that Six2 interacts with the developmental gene regulatory network in the developing palate.

Influence of periconception smoking behavior on birth defect risk

BACKGROUND

Smoking is one of the most important modifiable risk factors for adverse maternal and neonatal outcomes. Smoking during pregnancy has been associated with fetal growth restriction, adverse pregnancy outcomes, and chronic adult diseases. Existing research has evaluated the risk of smoking on congenital defects. However, no studies have evaluated how periconception smoking affects birth defects.

OBJECTIVE

The purpose of this study was to assess the association of maternal smoking and the timing of periconception exposure with congenital birth defects.

STUDY DESIGN

This study was a population-based retrospective cohort of live births in Ohio from 2006-2015 with the use of data from birth certificates. Rates of cardiovascular, musculoskeletal, gastrointestinal, and neural tube birth defects were compared between a referent group of women who did not smoke and a group of women who smoked (1) during the preconception period of 3 months before conception only and not in the first trimester and (2) in the preconception period plus throughout the first trimester of pregnancy. Multivariate logistic regression was used to quantify the relationship between periconception smoking and the rate of birth defects after adjustment for maternal race, age, pregestational diabetes mellitus, and socioeconomic factors.

RESULTS

Of the 1,436,036 live births in the study period, 75% of mothers did not smoke during the preconception period or during pregnancy. There were 334,156 women (23.3%) who smoked during pregnancy; 6.0% of the population smoked preconception only, and 17.3% of the population smoked both during the preconception period and through the first trimester. Smoking during the preconception period only, even without first trimester exposure, was associated with a 40% increased risk of gastroschisis. Smoking that was limited to preconception only was not associated with any other individual birth defects. However, smoking through the first trimester was associated with a statistically significant increased risk of several defects that included gastroschisis and limb reduction and a composite outcome of any defect, even after adjustment for coexisting factors.

CONCLUSION

Smoking during the period of fetal organogenesis (during the first trimester of pregnancy) is associated with increased risk of some birth defects. In this study, we provide novel data that smoking during the few months before conception, even with cessation in the first trimester, may also pose a risk for fetal malformation such as gastroschisis. These findings highlight the importance of preconception women's public health education efforts and warrant further investigation.

Congenital malformations are associated with secondhand smoke among nonsmoking women: A meta-analysis

BACKGROUND

The association between active maternal smoking and congenital malformations is well established, but little is known about the association between secondhand smoke and congenital malformations. Moreover, studies regarding the association between congenital malformations and secondhand smoke have not yielded consistent results.

METHODS

In July 2018, we searched PubMed, EMBASE, and China Biology Medicine databases for observational studies characterizing the relationship between secondhand smoke and congenital malformations of offspring in nonsmoking women. Two reviewers independently decided on whether a study should be included, did data extraction, and assessed study quality. Pooled risks with 95% confidence intervals were calculated using either the fixed-effects models or random-effects models. Further subgroup analyses and sensitivity analyses were performed to explore the potential source of heterogeneity and to examine the robustness of risk estimates.

RESULTS

Thirty-three studies with a total of 31 944 cases and 32 335 controls were included. Secondhand smoke exposure was associated with an increased risk of congenital malformations (odds ratio = 1.92; 95% confidence interval 1.61-2.30). Secondhand smoke was correlated with significantly increased risk for digestive system (1.17 [1.05-1.32]), nervous system (1.74 [1.33-2.29]), and cardiovascular system (2.10 [1.32-3.35]) malformations and for oral clefts (1.87 [1.47-2.39]).

CONCLUSIONS

Secondhand smoke exposure increases the risk for overall and several organ-system malformations. These findings highlight the necessity of improving community awareness to prevent secondhand smoke exposure during the preconception and conception periods.

Increased Risk for Neurodevelopmental Disorders in Children With Orofacial Clefts

OBJECTIVE

Children with orofacial clefts (OFC) may have an increased risk of poor mental health. This study aimed to investigate the risk of psychiatric diagnoses in individuals with OFC, stratified by cleft type.

METHOD

A nationwide register-based cohort of all individuals born with nonsyndromic OFC in Sweden between 1973 and 2012 (n = 7,842) was compared to a matched cohort (n = 78,409) as well as to their unaffected siblings (n = 9,637). The risk of psychiatric diagnoses, suicide attempts, and suicides was examined by crude and adjusted Cox regression models. Effect modification by sex was investigated with interaction terms in the models.

RESULTS

Children with cleft lip (CL) had a significantly higher risk of any psychiatric disorder, intellectual disability, and language disorders; children with cleft lip and palate (CLP) had, in addition, an increased risk of autism spectrum disorder (ASD). Children with cleft palate only (CPO) had risk increases for the same diagnoses as children with CL and CLP, but with higher hazard ratios, and also for psychotic disorders, attention-deficit/hyperactivity disorder (ADHD), and other behavioral or emotional disorders in childhood. Sex stratification indicated higher risk increases among females in CL and CLP but not in CPO. Siblings without OFC were less likely to be diagnosed with any psychiatric disorder, intellectual disability, language disorder, ASD, or ADHD compared to their siblings with OFC.

CONCLUSION

Children with nonsyndromic clefts had a significantly higher risk of neurodevelopmental disorders. This risk is unlikely to be explained by familial influences such as inherited genetic or shared environmental factors.

Factors associated with congenital anomalies in Addis Ababa and the Amhara Region, Ethiopia: a case-control study

Background

The early stage of embryo development is extremely vulnerable to various teratogenic factors, leading to congenital anomalies. In Ethiopia, a significant number of babies are born with congenital anomalies, but the risk factors for the anomalies have never been studied. Understanding the specific risk factors for congenital anomalies is very essential to provide health education that aims at creating awareness and establishing preventive strategic plan/s. The main objective of this study was to assess the risk factors associated with congenital anomalies in Addis Ababa and the Amhara Region, Ethiopia.

Methods

A case-control study was conducted from January 1- June 30, 2015. The participants were recruited at the purposively selected hospitals in Addis Ababa and the Amhara Region. A total of 207 cases and 207 controls were included in the study. Cases were neonates, infants, and children 0-11 months of age with external and internal major congenital anomalies diagnosed by pediatricians. Controls were neonates, infants, and children 0-11 months of age without external and internal anomalies. Data on sociodemographic characteristics, exposure to risk factors, and reproductive history were collected by face to face interviews with children’s mothers/caregivers using a structured questionnaire. Binary logistic regression was employed to explore risk factors associated with the occurrence of the problems.

Results

About 87.4% of the children were below 6 months, and 12.6% were between 6 and 11 months. The majority (59.9%) of the children were male, with the M: F sex ratio of 1.49. The mean age of the mothers was 26 years (16-45 years). Unidentified medication use during early pregnancy (AOR = 4.595; 95% CI: 1.868-11.301, P-value = 0.001), maternal alcohol drinking (AOR = 2.394; 95% CI: 1.212-4.726, P-value = 0.012), and exposure to chemicals (AOR = 9.964; 95% CI = 1.238-80.193, P-value = 0.031) were significantly associated with the occurrence of congenital anomalies. Iron folate use (AOR = 0.051; 95% CI: 0.010-0.260, P-value = < 0.001) before and during early pregnancy had a protective effect on congenital anomaly.

Conclusion

Unidentified medication use, alcohol drinking during early pregnancy, and exposure to chemicals had a significant association with the occurrence of congenital anomalies, whereas iron folate use before and during early pregnancy had a protective effect from congenital anomalies.

Risk factors and comorbidities in Brazilian patients with orofacial clefts

Considering that environmental risk factors substantially contribute to the etiology of orofacial clefts and that knowledge about the characteristics and comorbidities associated with oral clefts is fundamental to promoting better quality of life, this study aimed to describe the risk factors, main characteristics, and comorbidities of a group of patients with cleft lip and/or cleft palate (CL/P) from Rio Grande do Norte (RN), Brazil. Data were obtained from 173 patients with CL/P using a form from the Brazilian database on Orofacial Clefts. Most patients were male with cleft lip and palate and had a normal size and weight at birth; presented few neonatal intercurrent events; and had anemia and respiratory and cardiovascular diseases as main associated comorbidities. They also required timely surgical rehabilitation and multidisciplinary care to stimulate their neuropsychomotor development. In addition, a high frequency of familial recurrence and of parental consanguinity was evidenced in the studied population, especially for the cleft lip and cleft palate type. Other relevant findings were the considerable maternal exposure to alcohol, infections, smoking, and hypertension, as well as low supplementation with vitamins and minerals and deliberate consumption of analgesics, antibiotics, and antihypertensives during pregnancy. Characterization of the CL/P patient profile is essential for the planning of health services and integration among the health professionals involved in the diagnosis and treatment of these malformations. Our results reinforce the need for additional research to confirm the association between environmental factors and the development of orofacial clefts.

Is there an association between maternal smoking and oral clefts?

Data sourcesCochrane, PubMed and Ovid Medline. A search timeline of January 1966 to May 2015 was used and language was restricted to English.Study selectionCase-control and cohort studies relating to oral clefts, with information on maternal active smoking, before and after conception, excluding paternal smoking and exposure to environmental tobacco smoke.Data extraction and synthesisTwo authors extracted data independently. Both Begg's and Egger's funnel plots were used to assess publication bias. Sensitivity analysis was performed to assess impact of the different study types and chi-squared and P values were determined by SPSS software. Studies with missing data were excluded from the meta-analysis.ResultsA 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).ConclusionsWomen who smoke during pregnancy have a moderate risk of having a child with a CL +/- P or CP. A dose-response effect between maternal smoking and clefts was not established.

The impact of pre and perinatal lifestyle factors on child long term health and social outcomes: a systematic review

To understand the full extent of the impact of a trial, it is important to consider the long-term consequences of outcomes beyond the trial follow-up period, especially for early year's interventions. A systematic review of the literature associated with the long-term consequences of four key outcomes from the Building Blocks trial, specifically, low birth weight, smoking during pregnancy, interval to subsequent pregnancy and A&E attendance or inpatient admission was conducted. These factors were guided by the funders, the Department of Health, as being of particular interest in the UK context. Relevant studies were identified from a number of sources including large databases, reference checking and citation searching. The search yielded 3665 papers, 43 of which were considered appropriate for inclusion. Of these, 29 were relating to smoking during pregnancy, 13 to low birth weight, 0 to A&E attendances during early childhood and 1 to short (< 2 years) interval to subsequent pregnancy. Consistent associations were found between maternal smoking during pregnancy and the effects this has on children's health, educational attainment and likelihood of engaging in problem behaviour and criminal activity in later life. Low birth weight was also found to impact on children's long-term health and cognitive development. Subsequent pregnancies within two years of the previous birth were linked with increased likelihood of pre-term birth and neonatal death. Only minimal evidence was identified regarding the consequences of a short interval to second pregnancy and of child A&E and outpatient attendances. Given that these outcomes have been identified by the UK Department of Health as of particular interest for UK benefit, investment of research in these areas is recommended to establish a clearer picture of both short and long-term consequences.

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.

The Relationship between Orofacial Clefts and Material Deprivation in Wales

Objective:

This study investigated the relationship between material deprivation and the incidence of orofacial clefts (OFC) in South, West, and Central Wales, U.K.

Design and Setting:

The South, West, and Central Wales Orofacial-Cleft Register served as the primary data source for the study. Data on all children born with an orofacial cleft between 1982 and 2003 were geocoded to one of 844 geographic wards. National census data, similarly geocoded, served as the population denominator. Townsend's index of material deprivation was used to assign wards to one of seven levels of deprivation. This permitted investigation of the association of orofacial clefts with material deprivation.

Results:

Between 1982 and 2003, there were 831 babies born with an orofacial cleft, equating to 109 clefts per 100,000 live births. The incidence of orofacial clefts ranged from 82 per 100,000 (95% confidence interval [C.I.] 64 to 102 per 100,000) in babies born to mothers residing in the least deprived areas to 127 per 100,000 (95% C.I., 112 to 144 per 100,000) in those living in the most deprived areas, a significant linear trend being apparent (p < .001). A statistically significant risk of 1.55 (95% C.I., 1.18 to 2.04) for orofacial clefts was apparent between most and least deprived septiles of deprivation.

Conclusions:

This study provides further evidence of an association between material deprivation and orofacial clefts. Further work is required to elicit the degree to which potential risk factors contribute to this association and to determine how deprivation predisposes to orofacial clefts.

Effects of environmental tobacco smoke on the oral health of preschool children

AIMS

This study investigated the association between the prevalence of oral health problems (caries, gingivitis, mucosal pigmentation and enamel defects in one to 5 year-old children exposed and not exposed to environmental tobacco smoke before and/or after birth. Exposure to environmental tobacco smoke (ETS) in childhood may have significant health effects.

METHODS

A structured questionnaire was used to collect data on a child's current and previous illnesses, oral health behaviours, dietary habits, parental smoking behaviours and parents' dental history. The intraoral examination recorded dental caries (dmfs), enamel defects, gingival health, melanin pigmentation and soft tissue health. Stimulated saliva was collected. Total sIgA levels were quantified using indirect competitive ELISA with a SalimetricsTM kit.

RESULTS

The 44 children (aged 15-69 months) recruited were divided into two groups: ETS and non-ETS (control). There were 22 children in each: 16 who were exposed to ETS during and after gestation were identified as the ETSB subgroup. Participants exposed to ETS were more likely to have had upper respiratory tract and middle ear infections during the neonatal period and had higher mean dmft, mean dmfs, mean percent of surfaces with demarcated opacities and mean GI than the non-ETS participants. The children exposed to ETS before and after birth had the highest occurrence of enamel opacities showed a higher risk for dental caries even though more children in this group used the recommended fluoride toothpaste (1000 ppm fluoride). Mothers who smoked either never breastfed their children or breastfed their children for less than the recommended period of 6 months. Children exposed to ETS were shown to have higher mean total sIgA (μg/ml) than the children in the control group.

CONCLUSIONS

Associations between ETS exposure before and after gestation and oral health, including salivary changes in young children were shown in the present study. Dental health professionals should include a question about household smoking in children's dental histories, which would allow opportunities to discuss the impact of smoking on child oral health. Longitudinal oral health studies should include a history of maternal smoking during pregnancy and afterwards.

Loss-of-Function GRHL3 Variants Detected in African Patients with Isolated Cleft Palate

In contrast to the progress that has been made toward understanding the genetic etiology of cleft lip with or without cleft palate, relatively little is known about the genetic etiology for cleft palate only (CPO). A common coding variant of grainyhead like transcription factor 3 ( GRHL3) was recently shown to be associated with risk for CPO in Europeans. Mutations in this gene were also reported in families with Van der Woude syndrome. To identify rare mutations in GRHL3 that might explain the missing heritability for CPO, we sequenced GRHL3 in cases of CPO from Africa. We recruited participants from Ghana, Ethiopia, and Nigeria. This cohort included case-parent trios, cases and other family members, as well as controls. We sequenced exons of this gene in DNA from a total of 134 nonsyndromic cases. When possible, we sequenced them in parents to identify de novo mutations. Five novel mutations were identified: 2 missense (c.497C>A; p.Pro166His and c.1229A>G; p.Asp410Gly), 1 splice site (c.1282A>C p.Ser428Arg), 1 frameshift (c.470delC; p.Gly158Alafster55), and 1 nonsense (c.1677C>A; p.Tyr559Ter). These mutations were absent from 270 sequenced controls and from all public exome and whole genome databases, including the 1000 Genomes database (which includes data from Africa). However, 4 of the 5 mutations were present in unaffected mothers, indicating that their penetrance is incomplete. Interestingly, 1 mutation damaged a predicted sumoylation site, and another disrupted a predicted CK1 phosphorylation site. Overexpression assays in zebrafish and reporter assays in vitro indicated that 4 variants were functionally null or hypomorphic, while 1 was dominant negative. This study provides evidence that, as in Caucasian populations, mutations in GRHL3 contribute to the risk of nonsyndromic CPO in the African population.

Epidemiology of congenital anomalies of the central nervous system in children in Enugu, Nigeria: A retrospective study

Background:

Congenital anomalies, including those of the central nervous system (CNS), are among the leading causes of morbidity, mortality, and fetal loss.

Objective:

To determine the prevalence and associated factors of CNS congenital anomalies in children.

Methods:

A cross-sectional retrospective study of children managed with CNS anomalies was undertaken. Relevant clinical data of identified cases based on standard case definitions were retrieved from their case record files. Data were analyzed using SPSS 20.0 while the level of statistical significance was set at P < 0.05.

Results:

Seventy-two cases of CNS anomalies were identified over the period under review; out of 7329 total pediatric admissions giving a prevalence of 0.98%. Spina bifida cystica, 49 (68.0%) was the most common of the five anomalies seen followed by congenital hydrocephalus 11 (15.3%). Fifty-seven (79.2%) of the mothers did not take periconceptional folic acid supplementation (P < 0.05) whereas 25 (34.7%), 6 (8.3%), and 1 (1.4%) reported history of febrile illness in the first trimester of pregnancy, alcohol use, and diabetes mellitus in pregnancy, respectively. Majority of the cases of spina bifida cystica (30 [61.2%]) seen had corrective surgeries while the overall case fatality rate was 1 (1.4%).

Conclusions:

Spina bifida cystica was the most common anomaly of the CNS seen in this study and majority of the mothers of affected children did not take periconceptional folic acid supplementation (P < 0.05). Efforts should be made to create awareness and apply adequate preventive health education models including the use of periconceptional folic acid supplementation as well as the provision of access to standard prenatal care to at risk mothers.

Indoor air pollution and the risk of orofacial clefts in a rural population in Shanxi province, China

BACKGROUND

Shanxi Province is a region in China with a high incidence of orofacial clefts (OFCs). Our objective is to investigate the effect of maternal exposure to indoor air pollution (IAP) from coal combustion and tobacco smoke on the risk of an infant being born with orofacial clefts.

METHODS

Data were derived from an ongoing population-based case-control study of major external structural birth defects in Shanxi Province. Subjects included 213 cases with OFCs and 1319 healthy babies born between November 2002 and December 2014 in four rural counties. Exposure information was collected by face-to-face interview with mothers within 1 week of delivery or pregnancy termination. The authors derived an exposure index by integrating a series of IAP-related characteristics concerning dwelling and lifestyle.

RESULTS

Increased odds of OFC were associated with IAP exposure from heating (adjusted odds ratio [aOR] = 2.4; 95% confidence interval [CI], 1.2-4.5) and from smoking (aOR = 1.8; 95% CI: 1.3, 2.5), but not with exposure from cooking (aOR = 0.9; 95% CI, 0.6-1.4). Compared with women without IAP exposure, the aORs of OFC for children of women with exposure indices of 1, 2, 3 and ≥ 4 were 1.1 (95% CI, 0.6-1.8), 1.4 (95% CI, 0.8-2.4), 1.8 (95% CI, 1.0-3.2), and 3.4 (95% CI, 1.6-7.4), respectively, demonstrating a clear dose-response trend (p < 0.001).

CONCLUSION

Periconceptional exposure to IAP from coal combustion and tobacco smoking may increase the risk of OFCs in offsprings of women in Shanxi Province. Birth Defects Research (Part A) 106:708-715, 2016. © 2016 Wiley Periodicals, Inc.

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.

Cleft lip and palate: diagnosis and management

Cleft lip and palate is the most common congenital facial anomaly in children, which can affect appearance, speech, hearing, growth, psychosocial wellbeing and social integration. This article provides an overview of the condition for the benefit of all health-care professionals.

Screening of Transforming Growth Factor Beta 3 and Jagged2 Genes in the Malay Population with Nonsyndromic Cleft Lip with or without Cleft Palate

Objective

To determine the prevalence of mutations in transforming growth factor beta 3 (TGFβ3) and Jagged2 genes and their association with nonsyndromic cleft lip with or without cleft palate (CL±P) patients.

Design

Cross-sectional study on nonsyndromic CL±P and noncleft patients.

Setting

Reconstructive clinic and outpatient dental clinic, Hospital Universiti Sains Malaysia.

Patients

Blood samples of 96 nonsyndromic CL±P and 96 noncleft subjects.

Main Outcome Measure

Prevalence and association of mutations in TGFβ3 and Jagged2 genes with nonsyndromic CL±P.

Results

Most of the nonsyndromic CL±P patients (53.1%) had left unilateral CLP. There were slightly more females (56.6%) compared with males. The prevalence of the mutations in the TGFβ3 gene was 17.7% (95% confidence interval [CI]: 9.5, 24.5) and in the Jagged2 gene was 12.5% (95% CI: 5.5, 18.5), which was higher compared with the noncleft group. For the TGFβ3 gene, there was no mutation in the coding region in either of the groups. All variants were single nucleotide polymorphisms located within the intronic flanking region. Two variants were identified (g.15812T>G and g.15966A>G) in both nonsyndromic CL±P and noncleft patients. However, the association was not significant ( P > .05). Three variants (g.19779C>T, g.19547G>A, and g.19712C>T) were identified in the Jagged2 gene among nonsyndromic CL±P and noncleft patients. Only g.19712C>T showed a significant association with nonsyndromic CL±P patients ( P = .039).

Conclusion

g.19712C>T might play a crucial role in the development of cleft lip and palate. To the best of our knowledge, this is the first report of the mutation found within intron 13 of the Jagged2 gene among nonsyndromic CL±P Malay patients.

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.

Analysis of potential oral cleft risk factors in the Kosovo population

The aim of this study was to analyze the association of potential risk factors such as positive family cleft history, smoking, use of drugs during pregnancy, and parental age with oral clefts in offspring within the Kosovo population. We conducted a population-based case-control study of live births in Kosovo from 1996 to 2005. Using a logistic regression model, 244 oral cleft cases were compared with 488 controls. We have excluded all syndromic clefts. Heredity increases the risk of clefts in newborns [odds ratio (OR) = 8.25, 95% confidence interval (CI) 3.12-23.52]. Clefts were also associated with smoking (OR = 1.87, 95% CI 0.75-4.08), use of drugs during pregnancy (OR = 2.25, 95% CI 0.82-5.12), increasing maternal age (OR = 1.83, 95% CI 1.42-2.49), and increasing paternal age (OR = 1.3, 95% CI 1.2- 1.4). We found heredity to be the most important factor for cleft occurrence in Kosovar newborns. Another significant potential risk factor for occurrence of clefts is the parental age. We found the use of drugs and smoking during pregnancy to be less significant.

Passive smoking in the etiology of non-syndromic orofacial clefts: a systematic review and meta-analysis

BACKGROUND

Studies have found a consistent positive association between maternal smoking and non-syndromic orofacial clefts (NSOFC). However, no comprehensive assessment of the association between NSOFC and passive smoking has been undertaken. This systematic review and meta-analysis explores the relationship between maternal passive smoking and NSOFC, and compares the associations between passive and active smoking.

METHODS AND FINDINGS

Search strategy, inclusion / exclusion criteria, and data extraction from studies reporting maternal passive smoking and NSOFC was implemented without language restrictions. Risks of bias in the identified studies were assessed and this information was used in sensitivity analyses to explain heterogeneity. Meta-analysis and meta-regression of the extracted data were performed. Egger's test was used to test for small study effects. Fourteen eligible articles were identified. Maternal passive smoking exposure was associated with a twofold increase in risk of NSOFC (odds ratio: 2.11, 95% confidence interval: 1.54-2.89); this was apparent for both cleft lip with and without palate (OR: 2.05, 95% CI: 1.27-3.3) and cleft palate (OR: 2.11, 95% CI: 1.23-3.62). There was substantial heterogeneity between studies. In the studies that provided data enabling crude and adjusted odd ratios to be compared, adjustment for potential confounders attenuated the magnitude of association to about a 1.5-fold increase in risk.

CONCLUSION

Overall, maternal passive smoking exposure results in a 1.5 fold increase in risk of NSOFC, similar to the magnitude of risk reported for active smoking, but there is marked heterogeneity between studies. This heterogeneity is not explained by differences in the distribution of cleft types, adjustment for covariates, broad geographic region, or study bias/quality. This thorough meta-analysis provides further evidence to minimize exposure to environmental tobacco smoke in policy making fora and in health promotion initiatives.

Classification, epidemiology, and genetics of orofacial clefts

Orofacial clefts (OFCs) include a broad range of facial conditions that differ in cause and disease burden. In the published literature, there is substantial ambiguity in both terminology and classification of OFCs. This article discusses the terminology and classification of OFCs and the epidemiology of OFCs. Demographic, environmental, and genetic risk factors for OFCs are described, including suggestions for family counseling. This article enables clinicians to counsel families regarding the occurrence and recurrence of OFCs. Although much of the information is detailed, it is intended to be accessible to all health professionals for use in their clinical practices.

Examining the timing of changes in cigarette smoking upon learning of pregnancy

OBJECTIVE AND METHOD

Timeline Follow-back interviews were conducted with 107 pregnant women enrolling in smoking cessation and relapse prevention clinical trials in the Burlington, VT area between 2006 and 2009 to examine the time course of changes in smoking between learning of pregnancy and the first prenatal care visit. We know of no systematic studies of this topic.

RESULTS

Women reported learning of pregnancy at 5.1±2.2 weeks gestation and attending a first prenatal care visit at 10.1±3.6 weeks gestation. In the intervening five weeks, 22% of women became abstainers, 62% reduced their smoking, and 16% maintained or increased their smoking. Women who made changes typically reported doing so within the first 2 days after learning of pregnancy, with few changes occurring beyond the first week after learning of pregnancy.

CONCLUSION

In this first effort to systematically characterize the time course of changes in smoking upon learning of pregnancy, the majority of pregnant smokers who quit or made reductions reported doing so soon after receiving the news. Further research is needed to assess the reliability of these results and to examine whether devising strategies to provide early interventions for women who continue smoking after learning of pregnancy is warranted.

Women's perspectives on smoking and pregnancy and graphic warning labels

OBJECTIVES

To explore women's knowledge, attitudes, and beliefs about adverse outcomes associated with smoking during pregnancy and which outcomes might motivate cessation; to explore reactions to graphic warnings depicting 2 adverse outcomes.

METHODS

Twelve focus groups were conducted with women of childbearing age who were current smokers.

RESULTS

Participants had low to moderate awareness of many outcomes and believed it was acceptable to smoke in the first trimester before knowledge of pregnancy. Perceived susceptibility to outcomes was low. Motivators included risk-focused information, especially serious risks to the baby (eg, stillbirth, SIDS). Graphic warnings produced strong reactions, especially the warning with a real photo.

CONCLUSIONS

Despite barriers to reducing rates of smoking during pregnancy, educational information and photos depicting babies' risks could motivate women to quit.

Pattern and factors associated with congenital anomalies among young infants admitted at Bugando medical centre, Mwanza, Tanzania

BACKGROUND

Congenital anomalies or birth defects are among the leading causes of infant mortality and morbidity around the world. The impact of congenital anomalies is particularly severe in middle- and low-income countries where health care resources are limited. The prevalence of congenital anomalies varies in different parts of the world, which could reflect different aetiological factors in different geographical regions.

METHODS

Between October 2012 and January 2013, a cross-sectional study was conducted involving young infants below 2 months of age, admitted at a university teaching hospital in Tanzania. Face-to-face interviews with parents/caretakers of young infants were carried out to collect socio-demographic and clinical information. Physical examinations were performed on all young infants. Echocardiography, X-ray, cranial as well as abdominal ultrasonographies were performed when indicated.

RESULTS

Analysis of the data showed that among 445 young infants enrolled in the study, the prevalence of congenital anomalies was 29%, with the Central Nervous System (CNS) as the most commonly affected organ system. Maternal factors that were significantly associated with congenital anomalies included the lack of peri-conceptional use of folic acid (OR = 3.1; 95% CI = 1.4-6.7; p = 0.005), a maternal age of above 35 years (OR = 2.2; 95% CI = 1.1-4.3; p = 0.024) and an inadequate attendance to antenatal clinic (OR = 2.1; 95% CI = 1.4-3.3; p < 0.001). Infant factors that were significantly associated with congenital anomalies were female sex, a birth weight of 2.5 kg or more, singleton pregnancy and a birth order above 4.

CONCLUSIONS

Due to the high prevalence of congenital anomalies observed in this particular context, the hospital should mobilize additional resources for an optimal and timely management of the patients with congenital anomalies. In this study, the proportion of women taking folic acid supplements during early pregnancy was very low. Efforts should be made to ensure that more women use folic acid during the peri-conceptional period, as the use of folic acid supplement has been linked by several authors to a reduced occurrence of some congenital anomalies.

Association of NAT1 and NAT2 genes with nonsyndromic cleft lip and palate

Nonsyndromic cleft lip and palate (NSCLP) is a common congenital deformity, often associated with environmental risk factors, including alcohol, smoking, drugs and radiation exposure. N-acetyltransferase (NAT)1 and NAT2 genes are involved in the detoxification and metabolic activation of numerous drugs and chemicals. The aim of the present study was to investigate whether genetic variations in these two genes and gene‑gene interactions are associated with NSCLP. We investigated eight NAT1 tag single nucleotide polymorphisms (SNPs) and five NAT2 tag SNPs, selected from HapMap data. These SNPs were examined for associations with NSCLP in 204 patients and 226 controls. Strong evidence of an association with NSCLP was identified for rs4921580 in the NAT1 gene, and haplotype analysis supported these findings. We also found a significant difference between NSCLP and control groups for rs1041983 in the NAT2 gene. The results of gene‑gene interaction analyses also indicated that the combination of rs4921580 (Cg+gg) x rs1041983 (Ct+tt) increased the risk of NSCLP. Thus, the present study provides evidence for the role of NAT1 and NAT2 variations in NSCLP, and indicates that interactions between the NAT1 and NAT2 genes may be important in susceptibility to NSCLP.

Maternal occupational exposure to polycyclic aromatic hydrocarbons and risk of oral cleft-affected pregnancies

OBJECTIVE

To evaluate whether there is an association between maternal occupational exposure to polycyclic aromatic hydrocarbons and oral clefts in offspring. This is the first human study of polycyclic aromatic hydrocarbons and clefts of which the authors are aware.

DESIGN

Case-control study.

SETTING, PARTICIPANTS

Data for 1997 to 2002 from the National Birth Defects Prevention Study, a large population-based case-control study in the United States, were analyzed. Maternal telephone interviews yielded information on jobs held in the month before through 3 months after conception. Two industrial hygienists independently assessed occupational exposure to polycyclic aromatic hydrocarbons; all jobs rated as exposed or with rating difficulty were reviewed with a third industrial hygienist to reach consensus on all exposure parameters. Logistic regression estimated crude and adjusted odds ratios with 95% confidence intervals for cleft lip with or without cleft palate and cleft palate alone.

RESULTS

There were 2989 controls (3.5% exposed), 805 cases of cleft lip with or without cleft palate (5.8% exposed), and 439 cases of cleft palate alone (4.6% exposed). The odds of maternal occupational exposure to polycyclic aromatic hydrocarbons (any versus none) during pregnancy was increased for cleft lip with or without cleft palate cases as compared with controls (odds ratio, 1.69; 95% confidence interval, 1.18 to 2.40); the odds ratio was 1.47 (95% confidence interval 1.02 to 2.12) when adjusted for maternal education. There was a statistically significant adjusted exposure-response relationship for cleft lip with or without cleft palate (Ptrend = .02). Odd ratios for cleft palate alone were not statistically significant.

CONCLUSIONS

Maternal occupational exposure to polycyclic aromatic hydrocarbons was associated with increased risk of cleft lip with or without cleft palate in offspring.

Prenatal substance abuse: short- and long-term effects on the exposed fetus

Prenatal substance abuse continues to be a significant problem in this country and poses important health risks for the developing fetus. The primary care pediatrician's role in addressing prenatal substance exposure includes prevention, identification of exposure, recognition of medical issues for the exposed newborn infant, protection of the infant, and follow-up of the exposed infant. This report will provide information for the most common drugs involved in prenatal exposure: nicotine, alcohol, marijuana, opiates, cocaine, and methamphetamine.

Oral cleft prevention program (OCPP)

Background

Oral clefts are one of the most common birth defects with significant medical, psychosocial, and economic ramifications. Oral clefts have a complex etiology with genetic and environmental risk factors. There are suggestive results for decreased risks of cleft occurrence and recurrence with folic acid supplements taken at preconception and during pregnancy with a stronger evidence for higher than lower doses in preventing recurrence. Yet previous studies have suffered from considerable design limitations particularly non-randomization into treatment. There is also well-documented effectiveness for folic acid in preventing neural tube defect occurrence at 0.4 mg and recurrence with 4 mg. Given the substantial burden of clefting on the individual and the family and the supportive data for the effectiveness of folic acid supplementation as well as its low cost, a randomized clinical trial of the effectiveness of high versus low dose folic acid for prevention of cleft recurrence is warranted.

Methods/design

This study will assess the effect of 4 mg and 0.4 mg doses of folic acid, taken on a daily basis during preconception and up to 3 months of pregnancy by women who are at risk of having a child with nonsyndromic cleft lip with/without palate (NSCL/P), on the recurrence of NSCL/P. The total sample will include about 6,000 women (that either have NSCL/P or that have at least one child with NSCL/P) randomly assigned to the 4 mg and the 0.4 mg folic acid study groups. The study will also compare the recurrence rates of NSCL/P in the total sample of subjects, as well as the two study groups (4mg, 0.4 mg) to that of a historical control group.

The study has been approved by IRBs (ethics committees) of all involved sites. Results will be disseminated through publications and presentations at scientific meetings.

Discussion

The costs related to oral clefts are high, including long term psychological and socio-economic effects. This study provides an opportunity for huge savings in not only money but the overall quality of life. This may help establish more specific clinical guidelines for oral cleft prevention so that the intervention can be better tailored for at-risk women.

ClinicalTrials.gov Identifier

NCT00397917

Orofacial clefts and risk factors in tehran, iran: a case control study

BACKGROUND

Non-syndromic cleft lip with or without cleft palate (CL/P) or cleft palate only (CPO) are orofacial clefts with multifactorial etiology. These include environmental factors and heterogeneous genetic background. Therefore, studies on different and homogenous populations can be useful in detecting related factors. The aim of the present study was to evaluate the risk factors in patients with non-syndromic cleft in Tehran, Iran.

METHODS

Data from 300 patients and 300 controls were collected between 2005 and 2010. Binary logistic regression analyses were used to calculate relative risk by odds ratio (OR) and %95 confidence interval.

RESULTS

Low maternal age (OR=1.06, 95% CI, 1.011-1.113), low socioeconomic status (OR=0.23, 95% CI, 0.007-0.074), maternal systemic disease (OR=0.364; 95% CI, 0.152-0.873) and passive smoking (OR=0.613, 95% CI, 0.430-0.874) increased the risk for CL/P and CPO. There was a significant difference in iron and folic acid use during pregnancy when the case and control groups were compared.

CONCLUSION

In assessing for orofacial cleft risk, we should consider lack of folic acid supplementation use, maternal age and systemic diseases and passive smoking as risk factors.

Global oral health inequalities: challenges in the prevention and management of orofacial clefts and potential solutions

The birth prevalence of orofacial clefts, one of the most common congenital anomalies, is approximately one in 700 live births, but varies with geography, ethnicity, and socio-economic status. There is a variation in infant mortality and access to care both between and within countries, so some clefts remain unrepaired into adulthood. Quality of care also varies, and even among repaired clefts there is residual deformity and morbidity that significantly affects some children. The two major issues in attempts to address these inequalities are (a) etiology/possibilities for prevention and (b) management and quality of care. For prevention, collaborative research efforts are required in developing countries, in line with the WHO approach to implement the recommendations of the 2008 Millennium Development Goals (www.un.org/millenniumgoals). This includes the "common risk factor" approach, which analyzes biological and social determinants of health alongside other chronic health problems such as diabetes and obesity, as outlined in the Marmot Health inequalities review (2008) (www.ucl.ac.uk/gheg/marmotreview). Simultaneously, orofacial cleft research should involve clinical researchers to identify inequalities in access to treatment and identify the best interventions for minimizing mortality and residual deformity. The future research agenda also requires engagement with implementation science to get research findings into practice.

Genetic basis of susceptibility to teratogen induced birth defects

Birth defects remain the leading cause of infant death in US. The field of teratology has been focused on the causes and underlying mechanisms of birth defects for decades, yet our understanding of these critical issues remain unacceptably vague. Conclusions from years of animal and human studies made it clear that the vast majority of birth defects have multifactorial origins, with contributions from environmental and genetic factors. The environment comprises not only of the physical, biological, and chemical external environment surrounding the pregnant woman, but it also includes the internal environment of the woman's body that interact with the developing embryo in a complex fashion. The importance of maternal and embryonic genetic factors consisting of countless genetic variants/mutations that exist within every individual contribute to birth defect susceptibility is only now being more fully appreciated. This great complexity of the genome and its diversity within individuals and populations seems to be the principal reason why the same teratogenic exposure can induce severe malformation in one embryo, while fail to do so to other exposed embryos. As the interaction between genetic and environmental factors has long been recognized as the first "Principle of Teratology" by Wilson and Warkany [1965. Teratology: Principles and techniques. Chicago: University of Chicago Press], it is only recently that the appropriate investigative tools have been developed with which to fully investigate this fundamental principle. The introduction of high throughput technologies like whole genome sequencing or genome-wide association studies are promising to deliver an enormous amount of new data that will shed light on the genomic factors that contribute susceptibility to environmental teratogens. In this review, we attempt to summarize the epidemiological and experimental literature concerning birth defects whose phenotypic expression can be clearly related to the interactions between several select environmental factors and those genetic pathways in which they are most likely to have significant modifying effects. © 2011 Wiley-Liss, Inc.

Maternal smoking in pregnancy and birth defects: a systematic review based on 173 687 malformed cases and 11.7 million controls

BACKGROUND

There is uncertainty over whether maternal smoking is associated with birth defects. We conducted the first ever comprehensive systematic review to establish which specific malformations are associated with smoking.

METHODS

Observational studies published 1959–2010 were identified (Medline), and included if they reported the odds ratio (OR) for having a non-chromosomal birth defect among women who smoked during pregnancy compared with non-smokers. ORs adjusted for potential confounders were extracted (e.g. maternal age and alcohol), otherwise unadjusted estimates were used. One hundred and seventy-two articles were used in the meta-analyses: a total of 173 687 malformed cases and 11 674 332 unaffected controls.

RESULTS

Significant positive associations with maternal smoking were found for: cardiovascular/heart defects [OR 1.09, 95% confidence interval (CI) 1.02–1.17]; musculoskeletal defects (OR 1.16, 95% CI 1.05–1.27); limb reduction defects (OR 1.26, 95% CI 1.15–1.39); missing/extra digits (OR 1.18, 95% CI 0.99–1.41); clubfoot (OR 1.28, 95% CI 1.10–1.47); craniosynostosis (OR 1.33, 95% CI 1.03–1.73); facial defects (OR 1.19, 95% CI 1.06–1.35); eye defects (OR 1.25, 95% CI 1.11–1.40); orofacial clefts (OR 1.28, 95% CI 1.20–1.36); gastrointestinal defects (OR 1.27, 95% CI 1.18–1.36); gastroschisis (OR 1.50, 95% CI 1.28–1.76); anal atresia (OR 1.20, 95% CI 1.06–1.36); hernia (OR 1.40, 95% CI 1.23–1.59); and undescended testes (OR 1.13, 95% CI 1.02–1.25). There was a reduced risk for hypospadias (OR 0.90, 95% CI 0.85–0.95) and skin defects (OR 0.82, 0.75–0.89). For all defects combined the OR was 1.01 (0.96–1.07), due to including defects with a reduced risk and those with no association (including chromosomal defects).

CONCLUSIONS

Birth defects that are positively associated with maternal smoking should now be included in public health educational materials to encourage more women to quit before or during pregnancy.

GENES AS INSTRUMENTS FOR STUDYING RISK BEHAVIOR EFFECTS: AN APPLICATION TO MATERNAL SMOKING AND OROFACIAL CLEFTS

This study uses instrumental variable (IV) models with genetic instruments to assess the effects of maternal smoking on the child's risk of orofacial clefts (OFC), a common birth defect. The study uses genotypic variants in neurotransmitter and detoxification genes relateded to smoking as instruments for cigarette smoking before and during pregnancy. Conditional maximum likelihood and two-stage IV probit models are used to estimate the IV model. The data are from a population-level sample of affected and unaffected children in Norway. The selected genetic instruments generally fit the IV assumptions but may be considered "weak" in predicting cigarette smoking. We find that smoking before and during pregnancy increases OFC risk substantially under the IV model (by about 4-5 times at the sample average smoking rate). This effect is greater than that found with classical analytic models. This may be because the usual models are not able to consider self-selection into smoking based on unobserved confounders, or it may to some degree reflect limitations of the instruments. Inference based on weak-instrument robust confidence bounds is consistent with standard inference. Genetic instruments may provide a valuable approach to estimate the "causal" effects of risk behaviors with genetic-predisposing factors (such as smoking) on health and socioeconomic outcomes.