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

A Systematic Review of the Application of Computational Technology in Microtia

Microtia is a congenital and morphological anomaly of one or both ears, which results from a confluence of genetic and external environmental factors. Up to now, extensive research has explored the potential utilization of computational methodologies in microtia and has obtained promising results. Thus, the authors reviewed the achievements and shortcomings of the research mentioned previously, from the aspects of artificial intelligence, computer-aided design and surgery, computed tomography, medical and biological data mining, and reality-related technology, including virtual reality and augmented reality. Hoping to offer novel concepts and inspire further studies within this field.

Patterns of co-occurring birth defects in children with anotia and microtia

Many infants with anotia or microtia (A/M) have co-occurring birth defects, although few receive syndromic diagnoses in the perinatal period. Evaluation of co-occurring birth defects in children with A/M could identify patterns indicative of undiagnosed/unrecognized syndromes. We obtained information on co-occurring birth defects among infants with A/M for delivery years 1999-2014 from the Texas Birth Defects Registry. We calculated observed-to-expected ratios (OER) to identify birth defect combinations that occurred more often than expected by chance. We excluded children diagnosed with genetic or chromosomal syndromes from analyses. Birth defects and syndromes/associations diagnosed ≤1 year of age were considered. We identified 1310 infants with non-syndromic A/M, of whom 38% (N = 492) were diagnosed with co-occurring major defects. Top combinations included: hydrocephalus, ventricular septal defect, and spinal anomalies (OER 58.4); microphthalmia and anomalies of the aorta (OER 55.4); and cleft lip with or without cleft palate and rib or sternum anomalies (OER 32.8). Some combinations observed in our study may represent undiagnosed/atypical presentations of known A/M associations or syndromes, or novel syndromes yet to be described in the literature. Careful evaluation of infants with multiple birth defects including A/M is warranted to identify individuals with potential genetic or chromosomal syndromes.

Factors associated with nonsyndromic anotia and microtia, Texas, 1999-2014

BACKGROUND

Few risk factors have been identified for nonsyndromic anotia/microtia (A/M).

METHODS

We obtained data on cases and a reference population of all livebirths in Texas for 1999-2014 from the Texas Birth Defects Registry (TBDR) and Texas vital records. We estimated prevalence ratios (PRs) and 95% confidence intervals (CIs) for A/M (any, isolated, nonisolated, unilateral, and bilateral) using Poisson regression. We evaluated trends in prevalence rates using Joinpoint regression.

RESULTS

We identified 1,322 cases, of whom 982 (74.3%) had isolated and 1,175 (88.9%) had unilateral A/M. Prevalence was increased among males (PR: 1.3, 95% CI: 1.2-1.4), offspring of women with less than high school education (PR: 1.3, 95% CI: 1.1-1.5), diabetes (PR: 2.0, 95% CI: 1.6-2.4), or age 30-39 versus 20-29 years (PR: 1.2, 95% CI: 1.0-1.3). The prevalence was decreased among offspring of non-Hispanic Black versus White women (PR: 0.6, 95% CI: 0.4-0.8) but increased among offspring of Hispanic women (PR: 2.9, 95% CI: 2.5-3.4) and non-Hispanic women of other races (PR: 1.7, 95% CI: 1.3-2.3). We observed similar results among cases with isolated and unilateral A/M. Sex disparities were not evident for nonisolated or bilateral phenotypes, nor did birth prevalence differ between offspring of non-Hispanic Black and non-Hispanic White women. Maternal diabetes was more strongly associated with nonisolated (PR: 4.5, 95% CI: 3.2-6.4) and bilateral A/M (PR: 5.0, 95% CI: 3.3-7.7). Crude prevalence rates increased throughout the study period (annual percent change: 1.82).

CONCLUSION

We identified differences in the prevalence of nonsyndromic A/M by maternal race/ethnicity, education, and age, which may be indicators of unidentified social/environmental risk factors.

Epidemiological Study of Neonatal Congenital Microtia in Shandong Province, China, 2011-2020

OBJECTIVE

Congenital microtia is a common congenital disease in newborns. The specific cause of congenital microtia is currently unknown. The main objective of this study is to elucidate the epidemiological characteristics of congenital microtia and explore the possible etiology of congenital microtia.

METHODS

Part of the newborn data from 2011 to 2020 in Shandong Province Birth Defects Monitoring Hospitals were randomly selected. The software GraphPad Prism 9 was used to analyze the data and draw figures.

RESULTS

A total of 4247 infants were diagnosed with congenital malformation among 149,525 newborns randomly selected from the Shandong Province Birth Defects Monitoring Hospitals. Among them, a total of 115 infants were diagnosed with congenital microtia. The mean incidence of microtia during 10 years was 76.14±21.93 per 100,000 infants. The mean incidence of microtia in infants with congenital malformation was 2.67±0.75%. The average incidence of male and female infants with microtia during 10 years were 86.93±23.22 and 64.18±32.71 per 100,000 infants, respectively. In terms of maternal age, the older the mother, the higher the incidence of microtia. In terms of the place of residence, rural infants have a higher incidence of microtia than urban infants.

CONCLUSIONS

The average incidence of microtia was 76.14±21.93 per 100,000 infants in Shandong Province, China, 2011-2020. The female-to-male incidence ratio was 1.45:1. The authors recommend that women choose to give birth at the age of 25 to 29. They hope that the government will take measures to improve the medical and health conditions in rural areas and improve parenting knowledge in rural areas. This can effectively reduce the prevalence of microtia in infants.

Predicting the Risk of Microtia From Prenatal Factors: A Hospital-Based Case-Control Study

Background

Although a wide range of risk factors for microtia were identified, the limitation of these studies, however, is that risk factors were not estimated in comparison with one another or from different domains. Our study aimed to uncover which factors should be prioritized for the prevention and intervention of non-syndromic microtia via tranditonal and meachine-learning statistical methods.

Methods

293 pairs of 1:1 matched non-syndromic microtia cases and controls who visited Shanghai Ninth People's Hospital were enrolled in the current study during 2017-2019. Thirty-nine risk factors across four domains were measured (i.e., parental sociodemographic characteristics, maternal pregnancy history, parental health conditions and lifestyles, and parental environmental and occupational exposures). Lasso regression model and multivariate conditional logistic regression model were performed to identify the leading predictors of microtia across the four domains. The area under the curve (AUC) was used to calculate the predictive probabilities.

Results

Eight predictors were identified by the lasso regression, including abnormal pregnancy history, genital system infection, teratogenic drugs usage, folic acid supplementation, paternal chronic conditions history, parental exposure to indoor decoration, paternal occupational exposure to noise and maternal acute respiratory infection. The additional predictors identified by the multivariate conditional logistic regression model were maternal age and maternal occupational exposure to heavy metal. Predictors selected from the conditional logistic regression and lasso regression both yielded AUCs (95% CIs) of 0.83 (0.79-0.86).

Conclusion

The findings from this study suggest some factors across multiple domains are key drivers of non-syndromic microtia regardless of the applied statistical methods. These factors could be used to generate hypotheses for further observational and clinical studies on microtia and guide the prevention and intervention strategies for microtia.