Congenital heart defects coexisting with omphalocele - the important prognostic factor

Introduction
The aim of this study was to evaluate the following parameters of fetuses and neonates with omphalocele: the prevalence of coexisting congenital heart defects (CHD), abnormalities in heart function and the impact of coexisting CHD on fetal and neonatal survival.

Material and methods
The study group consisted of 69 fetuses with omphalocele diagnosed and monitored at the Department of Prenatal Cardiology in our Institute in the years 2007-2017. The retrospective analisis of patients' data was performed. For statistical analysis we used Chi-square test, t-Student test and U Mann-Whitney test.

Results
In the studied group omphalocele was an isolated defect in 31.9% of the cases (22/69), in 68.1% (47/69) coexisting defects were present, in 49.3% (34/69) the coexisting defect was CHD. The most common CHD coexisting with omphalocele were ventricular septal defect (VSD), double outlet right ventricle (DORV) and atrio-ventricular septal defect (AVSD). Abnormalities of heart function were present in 43.5% (30/69) of fetuses with omphalocele: 23.5% (8/34) with normal heart anatomy and in 62.9% (22/35) with CHD. Statistically significant differences between the group with normal heart anatomy and the group with CHD regarded: Cardiovascular Profile Score (CVPS) (median 10 points vs median 9 points, U Mann-Whitney test p=0.034), neonatal birth weight(mean 3253 g vs median 2700 g, U Mann-Whitney test p=0.003), Apgar score (median 8 vs median 7, U Mann-Whitney test p=0.038) and survival rate until discharge from hospital (85% vs 52.9%, Chi-square test p=0.034). The comparison of data from 2007-2017 with data obtained from similar analysis performed in our center in 1999-2006, revealed significant improvement in the early detection of omphalocele (median 14.5 weeks of gestation vs mean 25.4 weeks of gestation), gestational age of delivery (mean 38 weeks of gestation vs mean 34 weeks of gestation) and survival rate until discharge both in neonates with normal heart anatomy and coexisting CHD (85% and 52.9% vs 70% and 23% respectively).

Conclusions
1. The presence of coexisting CHD is an important prognostic factor in fetuses and neonates with omphalocele, so early fetal echocardiography should be performed in every case of omphalocele. 2. During the last decade (2007-2017), in contrast to years 1999-2006, we observed significant improvement in early and complete prenatal diagnosis of omphalocele. 3. We observed improvement in strategy of obstetrical management resulting in delivering neonates in a more advanced gestational age both in the group with normal heart anatomy and the group with coexisting CHD.