Seasonality, Epidemiology and Outcome of Congenital Diaphragmatic Hernia in South West of Iran

Congenital diaphragmatic hernia in a middle-income country: Persistent high lethality during a 12-year period

BACKGROUND

In high- and middle-income countries, mortality associated to congenital diaphragmatic hernia (CDH) is high and variable. In Brazil, data is scarce regarding the prevalence, mortality, and lethality of CDH. This study aimed to analyze, in São Paulo state of Brazil, the temporal trends of prevalence, neonatal mortality and lethality of CDH and identify the time to CDH-associated neonatal death.

METHODS

Population-based study of all live births with gestational age ≥ 22 weeks, birthweight ≥400g, from mothers residing in São Paulo State, Brazil, during 2004-2015. CDH definition and its subgroups classification were based on ICD-10 codes reported in the death and/or live birth certificates. CDH-associated neonatal death was defined as death up to 27 days after birth of infants with CDH. CDH prevalence, neonatal mortality and lethality were calculated and their annual percent change (APC) with 95% confidence intervals (95%CI) was analyzed by Prais-Winsten. Kaplan-Meier estimator identified the time after birth that CDH-associated neonatal death occurred.

RESULTS

CDH prevalence was 1.67 per 10,000 live births, with a significant increase throughout the period (APC 2.55; 95%CI 1.30 to 3.83). CDH neonatal mortality also increased over the time (APC 2.09; 95%CI 0.27 to 3.94), while the lethality was 78.78% and remained stationary. For isolated CDH, CDH associated to non-chromosomal anomalies and CDH associated to chromosomal anomalies the lethality was, respectively, 72.25%, 91.06% and 97.96%, during the study period. For CDH as a whole and for all subgroups, 50% of deaths occurred within the first day after birth.

CONCLUSIONS

During a 12-year period in São Paulo State, Brazil, CDH prevalence and neonatal mortality showed a significant increase, while lethality remained stable, yet very high, compared to rates reported in high income countries.

Seasonal Variation of Congenital Diaphragmatic Hernia: A Review of the Literature and Database Report from the United States and Canada

INTRODUCTION

 The etiology of congenital diaphragmatic hernia (CDH) remains unknown and only 10 to 30% of patients have a genetic cause. Seasonal variation is known to contribute to the development of some congenital anomalies. Our aim was to investigate whether CDH births have seasonal variation.

MATERIALS AND METHODS

 A literature review was conducted for CDH and seasonality. Moreover, data from the CDH International Patient Registry Database were collected for infants with due dates between 2008 and 2014. Due dates were used to determine seasonal distribution of births. Birth rates per month in the United States and Canada were extracted from publicly available databases. Data were analyzed using analysis of variance and contingency tables.

RESULTS

 First, the literature review revealed 11 articles, of which 3 were eligible for inclusion. These studies reported conflicting results on seasonality of CDH. Second, we extracted due dates from the CDH International Patient Registry Database (1,259 patients) and found that there were fewer due dates in winter months (12.1 ± 4 patients/month) than in summer (16.7 ± 6 patients/month; p = 0.011) and fall months (16.3 ± 5 patients/month; p = 0.022). Although this trend was similar to that of all births in the United States and Canada, a lower incidence was observed in winter for CDH infants (20.2%) than for the general population (24.1%, p = 0.0012). CDH survival rate did not vary by season.

CONCLUSION

 This study provides evidence for a seasonal variation of CDH births. No causative link was established between CDH development and seasonality. Population-based studies with a focus on exposome data are needed to explain seasonal variation in CDH.

Crossing birth and mortality data as a clue for prevalence of congenital diaphragmatic hernia in Sao Paulo State: A cross sectional study

Background

Congenital diaphragmatic hernia (CDH) is a severe embryological defect that causes pulmonary hypoplasia and hypertension. The prevalence and mortality rate of CDH varies around the world and little information is available about CDH in Latin America. Our aim was to estimate the general prevalence, mortality rate, prevalence of associated anomalies and features related to the outcomes of CDH in newborns from São Paulo state, Brazil.

Methods

Population-based cross-sectional study based on data gathered from the Live Births Information System (SINASC) and the Mortality Information System (SIM) of children born in São Paulo state between January 1st, 2006, and December 31st, 2017.

Findings

From 7,311,074 total survival discharges between 2006 and 2017, 1,155 were CDH-related, resulting in a prevalence rate of 1:6329 (95%CI = 1/6715 - 1/5984) and a mortality rate of 63·72% (95%CI = 60.95 - 66.50), 510 presented complex associated anomalies (44·15%). Maternal data showed higher prevalence among older mothers (older than 35 years old: 2·13 per 10,000) and, also, women with more years of schooling (higher than 12 years: 1·99 per 10,000). Presence of associated anomalies (95%CI = 5.69-11.10), 1-min Apgar (95%CI = 1.44-2.95), maternal schooling (95%CI = 1.06-2.43) and birth weight (95%CI = 1.04-2.26) were the most significant features associated with mortality.

Interpretation

There was 1 CDH case for every 6329 newborns in São Paulo and the mortality rate among those cases was 63·72% - a high rate compared to other countries.

Funding

This study didn't receive any specific grant from any funding agency in the public, commercial or not-for-profit sectors.

Honeymoon Period in Newborn Rats With CDH Is Associated With Changes in the VEGF Signaling Pathway

Background: Patients with congenital diaphragmatic hernia (CDH) have a short postnatal period of ventilatory stability called the honeymoon period, after which changes in pulmonary vascular reactivity result in pulmonary hypertension. However, the mechanisms involved are still unknown. The aim of this study was to evaluate mechanical ventilation's effect in the honeymoon period on VEGF, VEGFR-1/2 and eNOS expression on experimental CDH in rats. Materials and Methods: Neonates whose mothers were not exposed to nitrofen formed the control groups (C) and neonates with left-sided defects formed the CDH groups (CDH). Both were subdivided into non-ventilated and ventilated for 30, 60, and 90 min (n = 7 each). The left lungs (n = 4) were evaluated by immunohistochemistry of the pulmonary vasculature (media wall thickness), VEGF, VEGFR-1/2 and eNOS. Western blotting (n = 3) was performed to quantify the expression of VEGF, VEGFR-1/2 and eNOS. Results: CDH had lower biometric parameters than C. Regarding the pulmonary vasculature, C showed a reduction in media wall thickness with ventilation, while CDH presented reduction with 30 min and an increase with the progression of the ventilatory time (honeymoon period). CDH and C groups showed different patterns of VEGF, VEGFR-1/2 and eNOS expressions. The receptors and eNOS findings were significant by immunohistochemistry but not by western blotting, while VEGF was significant by western blotting but not by immunohistochemistry. Conclusion: VEGF, its receptors and eNOS were altered in CDH after mechanical ventilation. These results suggest that the VEGF-NO pathway plays an important role in the honeymoon period of experimental CDH.

Prevalence and risk factors for congenital diaphragmatic hernia: A global view

PURPOSE

To determine the global prevalence for congenital diaphragmatic hernia (CDH) and identify CDH-related risk factors.

METHODS

Using a defined strategy, a systematic review of the literature was conducted according to PRISMA guidelines, searching for population-based epidemiological studies to evaluate the prevalence of CDH globally and per country. Studies containing overlapping populations or timeframes were excluded. CDH-related risk factors were calculated by meta-analysis using RevMan5.3 and expressed as risk ratio and 95% confidence interval.

RESULTS

Prevalence: Of 8230 abstracts screened, 30 full-text articles published between 1980 and 2019 were included. The overall prevalence of CDH was 2.3 in 10,000 births (16,710 CDH babies in 73,663,758 livebirths).

RISK FACTORS

From 9 studies we found that male sex [RR 1.38 (1.05-1.80), p=0.02] and maternal age >35 years [RR 1.69 (1.26-2.25), p=0.0004] were associated with CDH. Conversely, maternal black ethnicity resulted as a protective factor [RR 0.82 (0.77-0.89, p<0.00001].

CONCLUSION

This study reveals that there is a worldwide paucity of population-based studies, and those studies that report on prevalence and risk factors come from a small number of countries. The prevalence of CDH varies within and across geographical world regions. The main risk factors for CDH identified are male sex and older maternal age. More epidemiological studies, involving more world regions, are needed to identify possible strategies to help strengthen our understanding of the risk factors, provide clinicians with the tools necessary for prenatal and postnatal counseling, and inform policy makers on how to strategize CDH care in different parts of the world.

TYPE OF STUDY

Systematic review and meta-analysis.

LEVEL OF EVIDENCE

Level III.