Risk factors and demographics for microtia in South America: a case-control analysis

Demographic, Functional, and Risk Factors Characterization in Ecuadorian Mestizo Patients With Microtia: A Retrospective Study

OBJECTIVE

This paper compares demographic, morphological, functional, and risk factors between isolated and familial forms of microtia in Ecuadorian mestizo patients.

METHODS

The authors did an epidemiological, and retrospective study with 112 patients divided into isolated microtia (n = 91) and familial microtia (n = 21). Patients with syndromic microtia were not included.

RESULTS

In isolated microtia, the mean age was 11.80 ± 16.9, and the most prevalent age group was from 5 to 9 years, with 45.0%; males were 58.2%, and 91.2% of patients were born in a city above 2500 meters about sea level. In familial microtia, the mean age was 15.57 ± 17.2. There were no statistically significant differences between the analyzed variables. In isolated microtia, 41.8% of patients had bilateral involvement, 40.7% had grade 1 microtia in the right ear (RE), and grade 1 in the left ear was 47.3%; external auditory canal atresia of RE was present in 62.6%, and in left ear in 31.6%. External auditory canal atresia sidedness was mostly unilateral in both groups. Most patients did not have tags or pits (78% and 81% in RE and 85.7% and 71.4%). Most patients had moderate hearing loss in both ears.

CONCLUSION

The authors found an association between both microtia forms with external auditory canal atresia in RE; only 20% of patients had unilateral auricular tags or pits in both groups. The authors also found a high incidence (18.75%) of familial microtia, which suggests a distinct pathological genetic component than the more prevalent isolated cases. The authors found a high association of microtia cases from the Ecuadorian highlands above 2500 meters about sea level (over 90%). The presence of "social" intake of alcohol during pregnancy showed over twice the chance of having a child born with microtia.

[Analysis of risk factors for congenital auriclar deformity and its different types]

Objective:To Explore the clinical characteristics,risk factors,and differences in risk factors for different types of congenital auricular deformities,in order to provide theoretical basis for precise prevention and control of congenital auriclar deformity. Methods:Full-term newborns born in the Second Affiliated Hospital of Zhengzhou University from May 2022 to January 2023 were screened for auricle malformation, general information and data were collected,,and high-risk factors were investigated withself-made questionnaire.Using a case-control study method,newborns with auriclar deformities were selected as the case group and those without auriclar deformities during the same period were selected as the control group.A case-control study was conducted to analyze the incidence rate,high-risk factors,and differences in high-risk factors for different types of auricle deformities. Results:A total of 1 758 newborns （3 516 ears） were included in this study,including 562 newborns（927 ears） with auriclar deformities,the incidence of congenital malformations of the auricle is 26.37%.Among them,289 ears （8.22%） were helical rim deformity,244 ears （6.94%） were lidding/lop ear,166 ears （4.72%） were mixed deformities,131 ears （3.73%） were prominent/cup ear,79 ears （2.25%） were Stahl's ears,16 ears （0.46%） were abnormal conchal crus,and 2 ears （0.06%） were cryptotia.Maternal history of infection in early pregnancy（OR=1.513，95%CI 1.119-2.045）,previous miscarriage history（OR=1.300，95%CI 1.049-1.613）,and abnormal pregnancy（OR=1.278，95%CI 1.032-1.582） are risk factors for congenital auricular malformations.There was no statistically significant difference in the history of infection（χ²=1.877，P=0.391）,previous miscarriage（χ²=4.706，P=0.095）,and abnormal pregnancy（χ²=5.026，P=0.081） among mothers with helical rim deformity,lidding/lop ear,and mixed deformities. Conclusion:The incidence rate of congenital auricle deformity is high, with common malformations such as helical rim deformity, lidding/lop ear,and mixed deformities. Congenital auricular deformity is caused by various factors, the same risk factor has roughly the same impact on different types of morphological abnormalities.

Epidemiological Analysis and the Nomogram for Possible Risk Factors for Severe Microtia

BACKGROUND

Microtia is a severe congenital malformation of the external ear. This study aimed to explore the epidemiologic characteristics and the possible risk factors in patients with severe microtia in China, and integrate significant variables into a predictive nomogram.

METHODS

A total of 965 patients with microtia were included. This retrospective case study was conducted from July 2014 to July 2019 at Plastic Surgery Hospital in China. The detailed questionnaires concerning potential risk factors were completed and data were gathered. Chi-Square and Fisher tests were used to analyze the variables, and a multivariate logistic regression model was used to select variables related to severe microtia, and then construct a nomogram. The nomogram model was evaluated by the concordance index (C-index), calibration plot, and receiver operating characteristics (ROCs) curve. Bootstraps with 1000 resamples were applied to these analyses.

RESULTS

Of the 965 microtia patients, 629 (65.2%) were male and 867 (89.8%) were sporadic. The cases were observed more commonly in unilateral (83.1%) and right-sided (52.0%). And multiple malformations were observed in 392 (40.6%) cases. Multivariate logistic regression analysis showed that maternal age, miscarriage frequency, virus infection, anemia, using progesterone, paternal alcohol intake, and topography of living areas were associated with a higher risk of severe microtia. All the significant variables were combined into a predictive nomogram (C-index = 0.755,95% CI = 0.703-0.807). Higher prediction accuracy (adjusted C-index = 0.749) was further verified via bootstrap validation. The calibration plot showed good performance, and the ROCs curve analysis demonstrated high sensitivity and specificity.

CONCLUSIONS

Most microtia patients are male, sporadic, and accompanied by other malformations, which are similar to the phenotypic analysis results of other studies. A nomogram predicting severe microtia was constructed to provide scientific guidance for individualized prevention in clinical practice.

Does Prematurity Play a Role in Newborn Microtia-Anotia?

OBJECTIVE

Microtia-anotia (MA) describes a range of external ear anomalies which is commonly associated with various syndromes and malformations of the head and neck. Previous studies have suggested a strong association between MA and male sex, maternal diabetes, and Hispanic race/ethnicity. This study seeks to evaluate the associations between MA and preterm newborns in the United States.

METHODS

Population-based inpatient registry analysis was conducted. Kids' Inpatient Database (2016) was used to identify weighted in-hospital births with diagnosis of prematurity or MA. Demographic information was obtained, and odds ratios (ORs) were used to determine associations between prematurity and MA.

RESULTS

Among patients included in our dataset, 8.655% (326 285) were preterm and 0.016% (523) had MA. 0.003% (109) of patients were preterm and had MA. Preterm infants had 2.19 times the odds (95% C.I. = 1.78-2.69) of having MA when compared to the full-term population. The binary logistic regression model accounting for possible confounding variables produced an aOR of 1.48 (95% C.I. = 1.17-1.87) for the association between prematurity and MA.

CONCLUSION

Infants who are born preterm are more likely to have MA than full term infants. The current results will allow for improved risk stratification, maternal counseling, and interventions in the case of prematurity.

Bioinformatics analysis of candidate genes involved in ethanol-induced microtia pathogenesis based on a human genome database: GeneCards

OBJECTIVE

Ethanol used by women during pregnancy increases the risk for microtia in the foetus. Traditionally, laboratory experiments and Mouse Genome Informatics (MGI) have been used to explore microtia pathogenesis. The aim of this study was to screen and verify hub genes involved in ethanol-induced microtia and to explore the potential molecular mechanisms.

METHODS

Overlapping genes related to ethanol and microtia were acquired from the GeneCards database and filtered by confidence score. These genes were further analysed via bioinformatics. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis results were visualized with the clusterProfiler R package. A protein-protein interaction (PPI) network was constructed based on data from the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database.

RESULTS

Overall, 41 genes related to both ethanol and microtia were identified. The genes most relevant to ethanol-induced microtia pathogenesis included FGFR-2, FGFR-3, FGF-8, TP53, IGF1, SHH, CTNNB1, and PAX6, among others. Most genes were strongly enriched for tissue and organ development in GO analysis. Additionally, many genes were enriched in the Ras, FoxO, MAPK, and PI3K-Akt signalling pathways in KEGG analysis.

CONCLUSIONS

Bioinformatics analysis was conducted on genes currently known to be related to ethanol-induced microtia pathogenesis. We propose that mechanisms involving FGF-family genes, TP53, IGF1 and SHH contribute significantly to ethanol-induced microtia and the accompanying malformation of other structures.

Review of Preferential Suspicious Genes in Microtia Patients Through Various Approaches

Recently, an increasing trend of the birth prevalence of anotia/microtia is observed in China, contributed by changes of social environment and lifestyle. There seems to be no major breakthroughs in exact pathogenesis of microtia, though the research results related to molecular genetics unceasingly appear. In this review, the authors focus on the results of various research methods which the authors regard as the preferential suspicious gene pool to facilitate the exploration of the pathogenic genes of microtia, knowing that the mechanism of microtia is very complicated. The advantages and limitations of these various approaches will also be systematically delineated. The authors believe that this review will give a deep insight in the genetic research of microtia and help plastic surgeons manage congenital microtia more effectively.

High Altitude as a Cause of Congenital Heart Defects: A Medical Hypothesis Rediscovered in Ecuador

Background: There are ∼83 million people living at high altitude (>2500 m) worldwide who endure chronic hypoxia conditions. This article aims to analyze the relationship between high altitude, identified in several cities in Ecuador, and the prevalence of congenital heart disease (CHD). Methods: Set in Ecuador, this epidemiological observational cross-sectional study analyzes data over a range of 18 years (from 2000 to 2017), including 34,904 reported cases of CHD, with a mean of 1939 cases per year. Results: The mean prevalence rate of CHD found is 70.6 per 10,000 live newborns. A K-means analysis resulted in three clusters. Cluster 1 shows the lowest altitude and prevalence of CHD, with an average of 2619 m and 63.02 cases per 10,000 live newborns. Cluster 2 presents the second highest altitude and prevalence of CHD, with an average of 2909 m and 72.04 cases per 10,000 live newborns. Cluster 3 shows the highest values of altitude and prevalence of CHD, with an average of 3176 m and 86.62 cases per 10,000 live newborns. Pearson's coefficient is 0.979, so the correlation between the variables is positive. An altitude ranging from 2500 to 2750 m relates to a prevalence of CHD of ≤71 cases per 10,000 live newborns. An altitude ranging from 2751 to 3000 m relates to a prevalence of CHD of >71 and <89 cases per 10,000 live newborns. An altitude ranging between 3001 and 3264 m relates to a prevalence of CHD of ≥89 cases per 10,000 live newborns. Conclusions: The findings show that high altitude (>2500 m), ethnicity (Native American), rural locations, and limited access to health care are factors that influence and increase the prevalence rate of CHD. A correlation coefficient of 0.914 shows the direct relationship between high altitude and prevalence rates of CHD. For each year elapsed, the prevalence of CHD increased by 3.33 cases per 10,000 live newborns.

Risk factors associated with congenital defects that alter hearing or vision in children born in the city of Bogotá between 2002 and 2016

INTRODUCTION

Congenital defects affecting the auditory and visual capacity of newborns represent a public health problem as they result in substantial disability, directly impacting the quality of life of newborns and their families.

OBJECTIVE

To evaluate risk factors associated with congenital defects that alter hearing or vision in newborns in the city of Bogotá between 2002 and 2016.

METHOD

Data from the Bogotá Birth Defects Surveillance and Follow-up Program was used, which consolidated data regarding 167 ECLAMC study (Estudio Colaborativo Latino Americano de Malformaciones Congénitas, in spanish) variables in a case-control design to identify risk factors for birth defects after parents provided signed informed consent. Cases were defined as any newborn (alive or stillborn) with a weight greater than 500 g with any visual or hearing abnormality. Controls were defined as newborn in the same hospital and month with no birth defects. Groups were formed according to the case presentation as follows: isolated eye anomaly, isolated ear anomaly, polymalformative, syndromic, and teratogenic.

RESULTS

In total, 402,657 births were reviewed, of which 968 cases had some congenital defects that alter hearing or vision. An association was found between the presence of defects and prematurity, as well as between syndromic cases and increasing maternal age. When comparing cases and controls with the risk of having a birth defect, multiparity had an odds ratio (OR) of 1.47 (95% CI: 1.27-1.71), acute respiratory infection had an OR of 2.41 (95% CI: 1.04-5.58), low maternal education level had an OR of 1.34 (95% CI:1.10-1.62), low paternal education had an OR of 1.42, (95% CI:1.17-1.73), manual labor in the maternal occupation had an OR of 1.31 (95% CI:1.03-1.67), and a history of congenital anomalies in the family had an OR of 1.55 (95% CI:1.19-2.00).

CONCLUSION

This research allowed the identification of epidemiological data and significant risk factors for congenital defects that alter hearing or vision in the population of Bogotá.

Hearing threshold of deaf pupils in Kaduna metropolis, Kaduna, Nigeria: A cross-sectional survey

Background

Hearing loss in paediatric age group may be inherited, developmental or caused by maternal rubella. It may also be due to complications at birth or certain infections such as meningitis and measles. Ototoxicity and exposure to excessive noise also contribute significantly. Majority of hearing loss in children can be prevented primarily. We aimed to share our findings on assessing the hearing thresholds of pupils in deaf schools in Northwestern Nigeria.

Participants and Methods

This was a cross-sectional study which assessed the hearing threshold of pupils in deaf schools in Kaduna metropolis, Kaduna, Nigeria. Approval was obtained from the State Ministry of Health Ethics Committee. Multi-staged sampling method was used to enrol 430 deaf pupils. Consent was obtained and a structured pre-tested questionnaire was used to generate data on the participant's biodata, history and detailed examination findings as well as pure-tone audiometry. Collated data were documented and entered into Statistical Product and Service Solutions version 20 for windows then analysed.

Results

Mean pure-tone average of the right ear was 103.4 ± 8.3 and the left ear was 104.3 ± 8.9. Majority had bilateral profound hearing loss (99.0%). Severe hearing loss was seen in 0.9%, whereas the remaining 0.1% had moderate hearing loss. The hearing loss sensorineural in majority (97.6%) and the remaining 2.4% had mixed hearing loss. High-frequency hearing loss predominated (98.6%).

Conclusion

Majority of the deaf pupils had bilateral, profound, sensorineural hearing loss, involving higher frequencies.

Evaluation of prenatal diabetes mellitus and other risk factors for craniofacial microsomia

OBJECTIVES

Craniofacial microsomia (CFM) is a congenital condition that typically involves hypoplasia of the ear and jaw. It is often associated with adverse effects such as hearing loss and sleep-disordered breathing. There is little research on its etiology.

METHODS

We conducted a case-control study from maternal interview data collected from mothers of infants with and without CFM. The study included 108 children with and 84 children without CFM. Logistic regression with adjustment for demographic factors was used to evaluate associations between maternal exposures of interest and risk for CFM overall, as well as for different phenotypic sub-groups of children on the CFM spectrum.

RESULTS

We found a statistically significant association between diabetes mellitus (DM) and CFM (OR 4.01, 95% CI 1.6-10.5). The association was slightly attenuated after adjustment for BMI. Higher parity was also associated with increased risk for CFM (OR 2.0, 95% CI 1.0-4.0). Vitamin A consumption and/or liver consumption was associated with a 70% lower risk compared with non-users (OR 0.3, 95% 0.1-0.8). Maternal age at the time of pregnancy was not associated with CFM.

CONCLUSIONS

These analyses contribute evidence linking maternal DM with an elevated risk of having an infant with CFM, which is consistent with previous research and adds to the body of knowledge about the strength of this association. Further study is warranted to understand the potential mechanisms underlying the effect of DM in the developing embryo.

Maternal risk factors for severe microtia/atresia in China: A case-control study

OBJECTIVE

Microtia/atresia is a severe malformation of the external ear. Previous studies have reported the potential risk factors on microtia, whereas few focused on severe microtia/atresia. The aim of the study was to investigate the effects of maternal exposure to environmental risk factors in patients with severe microtia/atresia in China.

METHODS

A case-control study was conducted. Cases were patients with severe microtia/atresia who presented to PUMCH between January 2014 and October 2017. A total of 322 patients with severe microtia/atresia were enrolled and 322 normal controls matched 1:1 with the patients by sex, age and nationality were enrolled. The designed questionnaires were completed and data were gathered. Odds ratios were estimated with logistic regression models along with 95% confidence intervals in severe microtia/atresia.

RESULTS

Most cases were males(68.6%), and the cases were observed more common in unilateral(80.7%), right-sided (54.0%). Multivariate logistic regression analysis showed that threatened abortion (OR 4.066,95% CI = 2.360-7.007), NSAIDs (OR 2.576,95% CI = 1.079-6.148), virus infection (OR 1.933,95% CI = 1.148-3.256), anemia (OR 1.902,95% CI = 1.026-3.526), miscarriages (OR 1.804,95% CI = 1.425-2.285), maternal age (OR 1.079,95% CI = 1.015-1.148) and paternal age (OR 1.061,95% CI = 1.003-1.122) were associated with a higher risk of severe microtia/atresia.

CONCLUSION

These results support that some maternal risk factors could be associated with severe microtia/atresia.

Altitude as a risk factor for the development of hypospadias. Geographical cluster distribution analysis in South America

OBJECTIVE

Hypospadias is the most common congenital anomaly affecting the genitals. It has been established as a multifactorial disease with increasing prevalence. Many risk factors have been identified such as prematurity, birth weight, mother's age, and exposure to endocrine disruptors. In recent decades multiple authors using surveillance systems have described an increase in prevalence of hypospadias, but most of the published literature comes from developed countries in Europe and North America and few of the published studies have involved cluster analysis. Few large-scale studies have been performed addressing the effect of altitude and other geographical aspects on the development of hypospadias. Acknowledging this limitation, we present novel results of a multinational spatial scan statistical analysis over a 30-year period in South America and an altitude analysis of hypospadias distribution on a continent level.

METHOD

A retrospective review was performed of the Latin American collaborative study of congenital malformations (ECLAMC). A total of 4,020,384 newborns was surveyed between 1982 and December 2011 in all participating centers. We selected all patients with hypospadias. All degrees of clinical severity were included in the analysis. Each participating center was geographically identified with its coordinates and altitude above sea level. A spatial scan statistical analysis was performed using Kulldorf's methodology and a prevalence trend analysis over time in centers below and above 2000 m.

RESULTS

During the study period we found 159 hospitals in six different countries (Colombia, Bolivia, Brazil, Argentina, Chile, and Uruguay) with 4,537 cases of hypospadias and a global prevalence rate of 11.3/10,000 newborns. Trend analysis showed that centers below 2000 m had an increasing trend with an average of 10/10,000 newborns as opposed to those centers above 2000 m that showed a reducing trend with an average prevalence of 7.8 (p = 0.1246). We identified clusters with significant increases of prevalence in five centers along the coast at an average altitude of 219.8 m above sea level (p > 0.0000). Reduction in prevalence was found in clusters located in two centers on the Andes mountains. Altitude of 2,000 m was associated with hypospadias (Figure), with an OR 0.59 (0.5-0.69). There are ethnic arguments to support our results supported by protective polymorphism distribution in high lands.

CONCLUSION

Altitude above 2,000 m is suggested to have a protective effect for hypospadias. Specific clusters have been identified with increased risk for hypospadias. Environmental risk factors in these areas need to be further studied given the association seen between altitude and the distribution of more severe cases.

Phenotypic characterization and risk factors for microtia in East China, a case-control study

OBJECTIVE

Although congenital microtia has been reported in various studies, little is known about the etiology of isolated and sporadic cases. The aim was to analyze potential risk factors for isolated and sporadic microtia using case-control study in East China.

METHODS

The study analyzed data from the hospital-based recruitment for deliveries between 2007 and 2013. Nine hundred eleven patients with microtia enrolled in the phenotypic characterization analysis, and then were adjusted by sex, age, region, syndrome and family history to compare with 562 random normal controls for potential risk factors.

RESULTS

Microtia is observed more often in males (69.7%), and the cases were typically unilateral (74.0%), right-sided (57.2%), sporadic (92.0%) and isolated (69.5%). Mothers of children with microtia were more likely to have suffered a periconceptional cold-like syndrome as well as to have had a history of previous spontaneous abortion. Inflammatory infection (aOR, 3.56; 95% CI, 2.07-6.13) and chemical exposure (aOR, 2.77; 95% CI, 1.78-4.32) was associated with a higher risk of microtia. However, threatened abortion was not the risk factor (aOR, 1.14; 95% CI, 0.78-1.67), using progesterone may increase the risk (aOR, 1.92; 95% CI, 1.03-3.59).

CONCLUSION

The results of phenotypic characterization analysis were similar to other studies. By controlling the effects of potential confounders, some risk factors could be teratogens of isolated and sporadic microtia in East China.