Types of coronary vasculature in the human fetus: an autopsy study

The heart receives blood from 2 vessels: the right and the left coronary arteries. Depending on the relationship between these 2 vessels, types with the right, the left or with neither coronary artery predominating can be distinguished. The incidence of particular types varies according to different reports. All available data regarding this issue come from studies where adult subjects were examined. There is no research in this field involving human fetuses. We examined 199 fetuses of both sexes (101 males and 98 females), 3-8 months of intrauterine life. All cases were derived from the Department of Histology and Embryology, Nicolaus Copernicus University. Prior to examination, all fetuses had been conserved in a 9% formaldehyde solution for over 3 months. We obtained the following results: type I vasculature, having equally developed coronary arteries, was found in 59 cases (29.5%); type II, with the right coronary artery predominating, was found in 65 cases (32.5%), and type III, with the left coronary artery predominating, occurred in 76 cases (38%). The subtypes IIIA and IIIB were described in 50 (25%) and 26 (13%) of the type III subjects, respectively. These data differ from the adult material incidence of dominant left coronary artery. While it is the most frequently occurring type in human fetuses, it is the least common in adult subjects.