RESUMO
OBJECTIVE: To determine presence of spatial clustering or dispersion of pre and postnatally detected hypoplastic left heart syndrome (HLHS) and d-transposition of the great arteries (TGA) cases. STUDY DESIGN: This retrospective study examined all patients with a prenatal or postnatal diagnosis of HLHS or TGA who had an initial visit or hospitalization at our tertiary care center over a 5-year period from 2012 to 2016 (n = 105). Using geographic information systems software, the nearest neighbor ratio (NNR) tool was used to determine whether statistically significant clustering or dispersion occurred. RESULTS: Geographic clustering was observed among prenatally diagnosed pooled cases of HLHS and TGA and all total cases (NNR = 0.73 and 0.66, respectively), but not postnatally detected cases (NNR = 1.08). Notably, there was significant dispersion of postnatally detected TGA cases (NNR = 1.22) There was no pattern for prenatally detected TGA or HLHS when analyzed individually. CONCLUSIONS: The spatial distribution of HLHS and TGA is not random; these conditions occur in geographic clusters. Clustering of all patients in the study population and dispersion of postnatal diagnosis of TGA represent opportunities for improved delivery of fetal cardiac care.
