Prevalence and Descriptive Epidemiology of Omphalocele in Iowa, 2000-2019 Open Access

Lawrence, Sashawn (Spring 2022)

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Prevalence and Descriptive Epidemiology of Omphalocele in Iowa, 2000-2019

By Sashawn Lawrence



Background: Omphalocele is an abdominal wall defect in which all or part of the small intestine exists outside of the abdomen in a membranous sac. The epidemiology of omphalocele is not well-understood, with previous reports differing on prevalence estimates and child and parental characteristics associated with this defect. The aim of this study is to use data from a 20-year population-based sample of children with omphalocele to examine prevalence, as well as associations between omphalocele and selected child, maternal, and paternal risk factors.

Methods: For children delivered in Iowa during 2000-2019, data for children with omphalocele (n=235) were obtained from the Iowa Registry for Congenital and Inherited Disorders and for all live births and fetal deaths (n=781,113) from the Iowa Department of Public Health. These data were used to estimate omphalocele prevalence and associations with selected child, maternal, and paternal factors using log-binomial regression models. Crude and adjusted prevalence ratios and 95% confidence intervals were estimated for all case children and for those with a definite diagnosis (prenatal diagnosis and postnatal diagnosis), isolated omphalocele (no additional, major birth defect) and nonsyndromic omphalocele (no monogenic or chromosomal disorder).

Results: Prevalence (per 10,000 live births and fetal deaths) of omphalocele during 2000-2019 was 3.01 (95% confidence interval = 2.65, 3.42). The estimated annual percentage change was 1.56% per year (95% confidence interval = -0.69, 3.86). In multivariate analysis, male sex, plurality ≥ 2, advanced maternal age (≥ 35 vs. < 35 years), and other maternal race/ethnicity (vs. non-Hispanic White) were observed to be associated with an increased risk, whereas non-Hispanic Black and Hispanic maternal race/ethnicities were associated with a reduced risk. Subgroup analysis for case children with definite diagnosis and for those that presented with isolated or nonsyndromic omphalocele tended to yield similar results.

Conclusion: This is the longest temporal examination of population-based prevalence estimates for omphalocele in the US. Findings offer an increased understanding of selected child, maternal, and parental antecedents for omphalocele. Future studies with larger, more racially/ethnically diverse samples and data on additional risk factors are needed to understand the etiopathogenesis of this birth defect.

Table of Contents

Table of Contents

CHAPTER I: Public Health Significance... 1

CHAPTER II: Background and Literature Review... 3

CHAPTER III: Methods... 14

CHAPTER IV: Results... 17

CHAPTER V: Discussion... 19


FIGURE 1... 36

TABLE 1... 37

TABLE 2... 38

TABLE 3... 41

TABLE 4... 43

TABLE 5... 45

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