Background: Etiology of Conotruncal Heart Defects (CTDs) is poorly understood and varies geographically. In the USA, the incidence of Tetralogy of Fallot (TOF), transposition of great arteries (TGA), and truncus arteriosus (TA) is 3.9, 2.3, and 1 per 10,000 live births, respectively.
Aims: To characterize CTD mortality, morbidity, and the association between maternal characteristics and the incidence of TOF, TGA, and TA in the population of southern Israel comprising predominantly urban Jewish population (80%) and rural Arab Bedouins (20%).
Methods: We identified 339 CTDs [TOF (n=181), TGA (n=113), and TA (n=45)] cases among 253,240 births (1991-2011) in Soroka University Medical Center (SUMC), a tertiary hospital admitting all area births. The association between maternal characteristics and the incidence of the three CTDs was estimated using multivariate logistic regression.
Results: The incidence of TOF, TGA, and TA was 7.46, 4.7, and 1.77 per 10,000 live births. The CHD incidence in Arab Bedouins was twice that in Jews. The 1-year survival of TOF, TGA, and TA was 83.4%, 73.2%, and 75%, respectively. In a multivariate analysis, Bedouin descent (adjusted odds ratio [aOR] 1.78, p=0.002), maternal age> 35 years (aOR 2.23, p<0.001), and sibling's CHD (aOR 23.52, p<0.001) were associated with TOF; Bedouin descent (aOR 1.67, p=0.23), sibling's CHD (aOR 25.683, p<0.001), and maternal age> 35 years (aOR 2.102, p=0.002) were associated with TGA. In a univariate analysis, Bedouin descent (p=0.004), CHD in siblings (p<0.001), and recurrent miscarriages (p=0.029) were associated with TA.
Conclusion: Southern Israel has a significantly higher incidence of CTDs than reported. The higher incidence in Arab-Bedouins and association between siblings’ CHD suggest a genetic component. Genetic counseling and early fetal echocardiograms should be encouraged in the Arab-Bedouin population, which might ultimately reduce the incidence of these severe defects.
