Associated Malformations in Cases with Congenital Diaphragmatic Hernia

Article excerpt

Summary: Associated malformations in cases with congenital diaphragmatic hernia. The etiology of congenital diaphragmatic hernia (CDH) is unclear and its pathogenesis is controversial. Because previous reports have inconsistently noted the type and frequency of malformations associated with CDH, we assessed these associated malformations ascertained between 1979 and 2003 in 334,262 consecutive births. Of the 115 patients with the most common type of CDH, the posterolateral, or Bochdalek-type hernia, 70 (60.8%) had associated malformations. These included: chromosomal abnormalities (n=21, 30.0%); non-chromosomal syndromes (Fryns syndrome, fetal alcohol syndrome, De Lange syndrome, CHARGE syndrome, Fraser syndrome, Goldenhar syndrome, Smith-Lemli-Opitz syndrome, multiple pterygium syndrome, Noonan syndrome, and spondylocostal dysostosis); malformation sequences (laterality sequence, ectopia cordis); malformation complexes (limb body wall complex) and non syndromic multiple congenital anomalies (MCA) (n=30, 42.9%). Malformations of the cardiovascular system (n=42, 27.5%), urogenital system (n=27, 17.7%), musculoskeletal system (n=24, 15.7%), and central nervous system (n=15, 9.8%) were the most common other congenital malformations. We observed specific patterns of malformations associated with CDH which emphasizes the need to evaluate all patients with CDH for possible associated malformations. Geneticists and pediatricians should be aware that the malformations associated with CDH can often be classified into a recognizable malformation syndrome or pattern (57.1%).

Key-words: Congenital diaphragmatic hernia - Classification of birth defects - Congenital heart diseases - Congenital malformations.

INTRODUCTION

Congenital diaphragmatic hernia (CDH) is a relatively common birth defect with an incidence of around one in every 3,000 live births associated with high mortality and morbidity. CDH is defined as a protrusion of abdominal viscera into the thorax through an abnormal opening or defect that is present at birth. In some cases, this protrusion is covered by a membranous sac. In contrast, diaphragmatic eventrations are extreme elevations, rather than protrusions, of part of the diaphragm that is often atrophic and abnormally thin. CDH is often associated with potentially lethal lung hypoplasia and pulmonary hypertension. Despite advances in therapy, mortality remains high, especially among severely affected infants, and long-term morbidity among survivors is common (13). The most common type of CDH is the posterolateral, or Bochdalektype hernia, which accounts for 90%-95% of CDH cases (26). Other types of CDH include anterior, retrosternal orperisternal Morgagni hernias, central (septum transversum) hernias, and pars sternalis hernias. CDH is frequently associated with other congenital malformations. However, the frequency of the reported associated malformations for CDH ranges from 27 % to 63 % (2, 22). It is not well-established whether CDH are associated with specific types of malformations or specific organ systems (25). Advances in clinical genetics and descriptive epidemiology increased the delineation of multiple associated malformations into specific syndromes, and the role of case classification (20) should assist this research. We assessed the prevalence of CDH, and the frequency and the types of associated malformations in a geographically well-defined population.

PATIENTS AND METHODS

Patients for this study were ascertained from 334,262 consecutive births of known outcome recorded by our registry of congenital malformations, described previously (23). Only the most common type of CDH the posterolateral or Bochdalek-type hernia was taken into consideration for this study as it accounts for more than 90 % of the cases with CDH. This research project was reviewed and approved by the Ethics Committee of the Medical Faculty of Strasbourg following the World Medical Association Declaration of Helsinki. …