Prenatal and perinatal factors associated with isolated oral clefting

Impact of Prenatal Care on Newborn Complications for Infants with Cleft Lip with or Without Cleft Palate

OBJECTIVE

To determine the association between prenatal care and cleft lip with or without cleft palate (CL ± P) and examine differences in newborn complications among infants diagnosed with CL ± P as a function of prenatal care.

DESIGN

Population-based retrospective cohort study.

SETTING

2018 United States National Vital Statistics System-Natality component (NVSS-N) was used to examine nationwide birth certificate data.

PARTICIPANTS

3,414,338 infants from the 2018 National Vital Statistics System, of which 1,699 had CL ± P.

MAIN OUTCOME MEASURE

Diagnosis of CL ± P and presence of newborn complications as a function of prenatal care.

RESULTS

Significant differences were found among various infant- and mother-specific variables when baseline comparisons were made between infants with and without CL ± P. After controlling for baseline differences, results indicated decreased odds of a diagnosis of CL ± P in cases where overall adequate prenatal care was obtained (OR = .841; 95% CI .757, .934), including prenatal care beginning in the 1st trimester (OR = .839; 95% CI .750, .939) and an adequate number of prenatal visits received (OR = .864; 95% CI .764, .976). Of infants with CL ± P, reduced odds of the infant admitted to the neonatal intensive care unit (OR = .777; 95% CI .613, .985) or transferred (OR = .601; 95% CI .407, .888) were apparent when adequate prenatal care was received.

CONCLUSION

Results suggest adequate prenatal care not only reduces the likelihood of CL ± P in infants but may also decrease the severity of negative outcomes in infants diagnosed with CL ± P. These findings emphasize necessity for adequate prenatal care.

The Prevalence of Nonsyndromic Oral Clefts in Twins Compared to Singletons: The Association With Birth Weight

PURPOSE

To examine the prevalence of nonsyndromic oral clefts in twins compared to singletons in the United States and to evaluate the association between birth weight and nonsyndromic oral clefts.

DESIGN

A large population-based cross-sectional study was performed using the data from the US National Center for Health Statistics database in 2017.

PARTICIPANTS

Our sample consisted of 128 310 twins and 3 723 273 singletons.

METHODS

The variables collected were sociodemographic variables, environmental predictors, and clinical measures. Descriptive analysis, bivariate, and multivariate logistic regression were performed.

MAIN OUTCOME MEASURE

The main outcome variable in our study is nonsyndromic oral clefts.

RESULTS

The prevalence of nonsyndromic oral clefts was 5.22 per 10 000 in twins and 5.12 per 10 000 in singletons. Results show no significant risk of nonsyndromic oral clefts in twins compared to singletons (P = .92). There was a significant relationship between birth weight and infant diagnosed with nonsyndromic oral clefts (P = .01). Unadjusted odds ratio for birth weight was 2.52 (95% CI: 2.25-2.82). Adjusted odds for potential confounders such as mother's age, race, mother's education, gender of the infant, APGAR 5-minute score, gestational age, prenatal smoking, number of prenatal care visits, and mother's body mass index were resulted in similar but with a slightly lower odds of 2.11 (95% CI: 1.78-2.50).

CONCLUSION

Compared to singletons, twins did not have higher risk of nonsyndromic oral clefts. Infants with low birth weight were more prone to have nonsyndromic oral clefts.

Genetic Factors in Nonsyndromic Orofacial Clefts

Orofacial clefts (OFCs) are the most common congenital birth defects in humans and immediately recognized at birth. The etiology remains complex and poorly understood and seems to result from multiple genetic and environmental factors along with gene-environment interactions. It can be classified into syndromic (30%) and nonsyndromic (70%) clefts. Nonsyndromic OFCs include clefts without any additional physical or cognitive deficits. Recently, various genetic approaches, such as genome-wide association studies (GWAS), candidate gene association studies, and linkage analysis, have identified multiple genes involved in the etiology of OFCs. This article provides an insight into the multiple genes involved in the etiology of OFCs. Identification of specific genetic causes of clefts helps in a better understanding of the molecular pathogenesis of OFC. In the near future, it helps to provide a more accurate diagnosis, genetic counseling, personalized medicine for better clinical care, and prevention of OFCs.

A comprehensive analysis of AHRR gene as a candidate for cleft lip with or without cleft palate

Cleft lip and palate (CL/P) is among the most common congenital malformations and affects 1 in 700 newborns. CL/P is caused by genetic and environmental factors (maternal smoking, alcohol or drug use and others). Many genes and loci were associated with cleft lip/palate but the amount of heterogeneity justifies identifying new causal genes and variants. AHRR (Aryl-Hydrocarbon Receptor Repressor) gene has recently been related to CL/P however, few functional studies analyze the genotypephenotype interaction of AHRR with CL/P. Several studies associate the molecular pathway of AHRR to CL/P which indicates this gene as a functional candidate in CL/P etiology.

METHODS

Systematic Literature Review was performed using PUBMED database with the keywords cleft lip, cleft palate, orofacial cleft, AHRR and synonyms. SLR resulted in 37 included articles.

RESULTS

AHRR is a positional and functional candidate gene for CL/P. In silico analysis detected interactions with other genes previously associated to CL/P like ARNT and CYP1A1. AHRR protein regulates cellular toxicity through TCDD mediated AHR pathway. Exposure to TCDD in animal embryos is AHR mediated and lead to cleft palate due to palate fusion failure and post fusion rupture. AHRR regulates cellular growth and differentiation, fundamental to lip and palatogenesis. AHRR decreases carcinogenesis and recently a higher tumor risk has been described in CL/P patients and families. AHRR is also a smoking biomarker due to changed methylation sites found in smokers DNA although folate intake may partially revert these methylation alterations. This corroborates the role of maternal smoking and lack of folate supplementation as risk factors for CL/P.

CONCLUSION

This research identified the importance of AHRR in dioxin response and demonstrated an example of genetic and environmental interaction, indispensable in the development of many complex diseases.

Maternal exposure to ambient air pollutant and risk of oral clefts in Wuhan, China

Maternal exposure to ambient air pollution has been related to oral clefts in offspring; however, the epidemiologic evidence is equivocal. Especially, the association between high levels of exposure to ambient air pollution during pregnancy and oral clefts remains unclear. The objective of this study was to evaluate whether high levels of maternal exposure to PM_2.5, PM₁₀, O₃, CO and SO₂ are related to increased risk of oral clefts in Wuhan, China. A population-based study was conducted using cohort of 105,927 live-born infants, fetal deaths, and stillbirths during a two-year period from 2011 to 2013. For each participant, weekly and monthly averages of daily mean concentrations for each pollutant were estimated. Multiple logistic regression analyses were constructed to quantify the adjusted odds ratios (aORs) for the relationship between each air pollutant and oral clefts while controlling for key covariates. Using monthly averages, a cleft lip with or without cleft palate (CLP) was associated with PM_2.5 (aORs _{2nd month} = 1.34, CI:1.19-1.49; aORs _{3rd month=}1.14, CI:1.02-1.28), PM₁₀ (aORs _{2nd month} = 1.11, CI:1.00-1.23) and CO (aORs _{2nd month} = 1.31, CI:1.14-1.51; aORs _{3rd month} = 1.17, CI:1.03-1.33). A cleft palate only (CPO) was associated with PM_2.5 (aORs _{2nd month} = 1.24, CI: 1.03-1.48), and O₃ (aORs _{2nd month} = 1.21, CI: 1.03-1.42; aORs _{3rd month} = 1.18, CI: 1.02-1.37). Our findings reveal an association between air pollutants exposure and the risk of oral clefts. Future studies are needed to confirm these associations, and clarify the causality related to specific pollutants during the most relevant vulnerable exposure time windows for oral clefts during pregnancy.

Ambient air pollution and birth defects in Haikou city, Hainan province

Background

Evidence shows exposure to ambient air pollution during pregnancy was associated with an increased risk of adverse birth outcomes, such as preterm birth, low birth weight and intrauterine growth retardation, but the results for birth defects have been inconsistent.

Methods

The data on birth defects was collected from the Birth Defects Monitoring Network of Haikou city. Air pollution data for PM₁₀, SO₂ and NO₂ were obtained from Haikou Environmental Monitoring Center. Logistic regression analysis was used to evaluate these associations.

Results

The risk of birth defects was related to PM₁₀ levels (adjusted OR = 1.039; 95% CI = 1.016-1.063) and SO₂ levels (adjusted OR = 0.843; 95% CI = 0.733-0.969) for the second month of pregnancy. In the third month of pregnancy, the risk of birth defects was also related to PM10 levels (adjusted OR = 1.066; 95% CI = 1.043-1.090) and SO₂ levels (adjusted OR = 0.740; 95% CI = 0.645-0.850).

Conclusion

The study provides evidence that exposure to PM₁₀ and SO₂ during the second and third month of pregnancy may associated with the risk of birth defects.

Increased prevalence of major congenital anomalies in births with placental abruption

OBJECTIVE

To examine the association between major congenital anomalies and placental abruption.

METHODS

A register-based retrospective case-control study was carried out from 1987 to 2005. Data on baseline characteristics and birth outcomes were collected from three Finnish national health registers: the Medical Birth Register, National Hospital Discharge Register, and Register of Congenital Malformations. The study population consisted of 4,190 women with singleton birth and placental abruption. Three control women without placental abruption were selected for each case, matched by maternal age, parity, year of birth, and hospital district. The main outcome measure of the study was a major congenital anomaly associated with placental abruption.

RESULTS

In total, 261 (prevalence 623/10,000) births with placental abruption and 415 (prevalence 330/10,000) control births had major congenital anomalies (odds ratio [OR] 1.92, 95% confidence interval [CI] 1.6-2.52). The association was strongest among births with growth restriction and prematurity. Adjusted analysis revealed a significant association with central nervous system anomalies (OR 2.33, 95% CI 1.29-4.23), anomalies of the eyes and ears (OR 1.82, 95% CI 1.08-3.09), cardiovascular anomalies (OR 1.78, 95% CI 1.34-2.37), respiratory anomalies (OR 3.51, 95% CI 1.56-7.90), gastrointestinal anomalies (OR 3.81, 95% CI 2.27-6.41), genitourinary anomalies (OR 2.55, 95% CI 1.73- 3.74), musculoskeletal anomalies (OR 1.67, 95% CI 1.24-2.24), and anomalies of integument (OR 3.29, 95% CI 1.20-8.98) in births complicated by placental abruption.

CONCLUSIONS

Major congenital anomalies are twice as common among neonates born from pregnancies complicated by placental abruption compared with control pregnancies without abruption. This observation applies to several organ systems.

LEVEL OF EVIDENCE

II.

Does the relationship between prenatal care and birth weight vary by oral clefts? evidence using South American and United States samples

OBJECTIVE

To evaluate if the association between prenatal care use and birth weight (BW) varies for infants with cleft lip and/or cleft palate (CL/P), classified into isolated and non-isolated forms, compared with unaffected infants.

STUDY DESIGN

The study employed 2 datasets. The first included a multi-country sample of 2405 infants with CL/P and 24046 infants without CL/P born in 1996-2007 in South America. The second was a sample of 2122 infants with CL/P and 297415 without CL/P from the United States 2004 natality dataset. Separate analyses were performed for the South American and United States samples. The association between prenatal care and BW was evaluated separately for isolated CL/P, non-isolated CL/P, and unaffected infants using regression models adjusting for several background characteristics.

RESULTS

Prenatal care was associated with improved BW for all infant groups, with greater BW increases for infants with CL/P particularly non-isolated forms. In the South American sample, BW increased by 108, 69, and 40 g on average per prenatal visit for infants with non-isolated CL/P, infants with isolated CL/P, and unaffected infants, respectively. In the United States sample, BW increased by 51, 21, and 16 g on average per prenatal visit for these infant groups, respectively.

CONCLUSIONS

Prenatal care was associated with larger BW increases for pregnancies complicated with CL/P, particularly non-isolated forms, compared with unaffected pregnancies. Given that reduced BW is a well-recognized comorbidity of CL/P, the findings highlight the importance of prenatal care for at-risk pregnancies as a tertiary-prevention intervention to reduce the health burden of CL/P.

Demographics of orofacial clefts in Canada from 2002 to 2008

Objective : Orofacial clefts such as cleft lip, cleft palate, and cleft lip and palate are the most frequent congenital anomalies of the head and neck. The purpose of this study was to determine the current demographics for orofacial clefts in Canada. Methods : A request for data from all Canadian provinces (excluding Quebec due to incompatibilities with provincial coding systems) for the fiscal years 2002-2003 to 2007-2008 was submitted to the Canadian Institute for Health Information. Variables evaluated included gender, cleft type, gestational age, birth weight, income quintile, and institution health region. Results : Over the period studied, the prevalence of orofacial clefts ranged from 11.0 to 15.3 per 10,000 live births (1 in 654 to 1 in 909 live births). The distribution of cleft types for live births with orofacial clefts was 17% for cleft lip, 41% for cleft palate, and 42% for cleft lip and palate, of which cleft lip and cleft lip and palate were male dominant (62% and 66% male, respectively) and cleft palate was female dominant (56% female). Saskatchewan and Manitoba had significantly higher cleft birthrates (P < .05) compared with the other provinces. Birth weight and gestational age (but not income quintile) were significantly (P < .0001) lower for newborns with orofacial clefting compared with those with no cleft. Conclusions : Canada has one of the highest orofacial cleft birthrates in the world (prevalence of 12.7 per 10,000 live births, approximately 1 in 790 live births). This study presents an updated demographic of orofacial clefts in Canadian newborns and may be useful in predicting the burden of anticipated health care.

Current concepts in genetics of nonsyndromic clefts

Nonsyndromic cleft lip and palate is a complex genetic disorder with variable phenotype, largely attributed to the interactions of the environment and multiple genes, each potentially having certain effects. Numerous genes have been reported in studies demonstrating associations and/or linkage of the cleft lip and palate phenotypes to alleles of microsatellite markers and single nucleotide polymorphisms within specific genes that regulate transcription factors, growth factors, cell signalling and detoxification metabolisms. Although the studies reporting these observations are compelling, most of them lack statistical power. This review compiles the evidence that supports linkage and associations to the various genetic loci and candidate genes. Whereas significant progress has been made in the field of cleft lip and palate genetics in the past decade, the role of the genes and genetic variations within the numerous candidate genes that have been found to associate with the expression of the orofacial cleft phenotype remain to be determined.

Enlarged nuchal translucency in chromosomally normal fetuses: strong association with orofacial clefts

OBJECTIVES

The aim of this study was to investigate whether there is an association between enlarged nuchal translucency (NT) and orofacial clefts.

METHODS

The pregnancy outcome of women who underwent an NT measurement between January 2000 and November 2008 was reviewed. All orofacial clefts detected prenatally and postnatally in karyotypically normal fetuses/infants were reviewed and a distinction was made between isolated defects and clefts as part of multiple congenital anomalies (associated).

RESULTS

The cohort included 8638 fetuses. The NT was enlarged in 746 (8.6%). The karyotype was normal in 8347 fetuses, including 513 of the fetuses with an enlarged NT. Isolated or associated cleft lip, with or without cleft palate (CL/P), or cleft palate (CP) were diagnosed in 18 chromosomally normal fetuses (an incidence of 2.2 per 1000). In eight of these cases the NT was normal (8/7834; an incidence of 1.0 per 1000) and in the remaining 10 it was enlarged (10/513; an incidence of 19.5 per 1000). CL/P and CP were isolated or associated in three and seven of the chromosomally normal fetuses with an enlarged NT, respectively. Euploid fetuses with an enlarged NT had a relative risk for any clefts of 19 and a relative risk for isolated or associated clefts of 8 and 53, respectively (P < 0.001).

CONCLUSIONS

Chromosomally normal fetuses with an enlarged NT have an increased risk of orofacial clefts. CL/P and CP are, in these fetuses, mostly associated findings, frequently part of a genetic syndrome. A detailed ultrasound examination with special attention given to the orofacial area is indicated in these fetuses.

Timeliness of Primary Cleft Lip/Palate Surgery

Objective:

To examine the timeliness of primary cleft surgery, mean age at which surgery occurred, and factors associated with timely cleft surgery among children with orofacial clefts (OFCs).

Design:

Retrospective study of children with OFC using North Carolina vital statistics, birth defects registry, and Medicaid files.

Participants/Patients:

Medicaid-enrolled North Carolina resident children with OFC born from 1995 to 2002.

Main Outcome Measures:

Proportion of children who underwent primary cleft surgery within 18 months of life, mean age when surgery occurred, and factors associated with timely surgery.

Results:

406 children with OFC were continuously enrolled in Medicaid during the first 2 years of life. Overall, 78.1% of children had surgery within 18 months. About 90% of children with cleft lip (CL), 58.0% of children with cleft palate (CP), and 89.6% of children with cleft lip and palate (CLP) received timely cleft surgery; the mean age at which surgery occurred was 5 months. Children whose mothers received maternity care coordination, received prenatal care at a local health department, or lived in the southeastern or northeastern region of the state were more likely to receive timely cleft surgery.

Conclusion:

Most children with OFC in North Carolina born during this time period received primary cleft surgery within 18 months of life, but this varied by maternal demographics and other factors.

A Population-Based Evaluation of Antenatal Diagnosis of Orofacial Clefts

Objectives:

To evaluate the changes in prevalence and antenatal detection of cleft lip with or without cleft palate and isolated cleft palate and to describe the association between anomalies and rates of antenatal diagnosis in Nova Scotia from 1992 to 2002.

Design:

This population-based cohort study employed the Nova Scotia Atlee Perinatal Database, the Fetal Anomaly Database, and IWK Cleft Palate Database in Halifax, Nova Scotia, Canada.

Outcome Measures:

Cleft type, mode of diagnosis, and associated abnormalities of orofacial clefts for liveborn infants, stillbirths, and second trimester terminations of pregnancy between 1992 and 2002 were determined.

Results:

There were 225 fetuses identified as having orofacial clefts. The overall prevalence of clefts was 2.1 in 1000 live births, and this prevalence did not change with time. The overall antenatal detection of cleft lip with or without cleft palate was 23%; however, there was improvement in detection of cleft lip with or without cleft palate from the years 1992 to 1996 (14%) to the years 1997 to 2002 (30%, p  =  .02). No isolated cleft palates were detected antenatally. Associated structural anomalies were seen in 34.2% of cases with orofacial clefts, and chromosomal abnormalities were associated with 9.8%.

Conclusions:

The prevalence of orofacial clefts in Nova Scotia has not changed from 1992 to 2002. The proportion of antenatally diagnosed cleft lip with or without cleft palate in Nova Scotia is consistent with rates reported in the literature and has increased from 1992 to 2002.

The Pittsburgh Oral-Facial Cleft study: expanding the cleft phenotype. Background and justification

The Pittsburgh Oral-Facial Cleft study was begun in 1993 with the primary goal of identifying genes involved in nonsyndromic orofacial clefts in a variety of populations worldwide. Based on the results from a number of pilot studies and preliminary genetic analyses, a new research focus was added to the Pittsburgh Oral-Facial Cleft study in 1999: to elucidate the role that associated phenotypic features play in the familial transmission patterns of orofacial clefts in order to expand the definition of the nonsyndromic cleft phenotype. The purpose of this paper is to provide a comprehensive review of phenotypic features associated with nonsyndromic orofacial clefts. These features include fluctuating and directional asymmetry, non-right-handedness, dermatoglyphic patterns, craniofacial morphology, orbicularis oris muscle defects, dental anomalies, structural brain and vertebral anomalies, minor physical anomalies, and velopharyngeal incompetence.

Descriptive epidemiology of oral clefts in a multiethnic population, Hawaii, 1986-2000

OBJECTIVE

To describe the relationship between oral clefts and demographic and clinical factors in Hawaii.

METHODS

Data were obtained from a birth defects registry and included all infants and fetuses with oral clefts delivered during 1986 through 2000. Subjects were categorized as total, isolated, and nonisolated cleft lip with or without cleft palate (CL+/-P) or cleft palate without cleft lip (CP).

RESULTS

There were 352 total subjects of CL+/-P and 192 total subjects of CP with corresponding rates per 10,000 live births of 12.5 for CL+/-P and 6.8 for CP. Total, isolated, and nonisolated CL+/-P rates demonstrated no clear pattern by maternal age. The total and nonisolated CP rates tended to be higher among older maternal age groups. The total CL+/-P rate was higher among Far East Asians, Pacific Islanders, and Filipinos than among whites. The total CP rate was higher among Far East Asians and Pacific Islanders than among whites, whereas the rate for Filipinos was lower than for whites. The total CL+/-P rate was substantially lower among females (rate ratio 0.62, 95% confidence interval [CI] = 0.49 to 0.77) and the total CP rate substantially higher among females (rate ratio 1.52, 95% CI = 1.13 to 2.06). Both CL+/-P and CP were more common with lower birth weight and gestational age among the total, isolated, and nonisolated groups.

CONCLUSIONS

Oral cleft risk was associated with maternal race/ethnicity, sex, birth weight, and gestational age. Although some of the observed associations were consistent with the literature, others were not.

Birth weight and gestational age of newborns with cleft lip with or without cleft palate and with isolated cleft palate

The birth weight and gestational age of 1368 newborns with isolated cleft lip with or without cleft palate and 582 with isolated cleft palate were compared to those of matched healthy controls. The results indicate that fetuses with oral clefts are at elevated risk of having low and very low birth weight, but not of having a premature birth. Speculations on a relationship between these findings and the presence of oral clefts are presented.