Morphometric methods were used to study the great arterial trunks in a total of 22 human fetuses and newborn subjects weighing from 1 to 3.8 kg (mean 2.22 ± 0.85 kg). All specimens displayed concordant atrioventricular and ventriculoarterial connections, and all had perimembranous ventricular septal defects. Thirteen different parameters were measured in each specimen, comprising the orifices of the great arterial trunks, ascending aorta, vessels branching from the aortic arch, the aortic isthmus, descending aorta, pulmonary trunk, orifices of the pulmonary arteries, and arterial duct. The values were Compared with patterns of normality established in an earlier study using hearts from 496 human fetuses and neonates weighing form 60 to 5000 g. Minimum square regression analyses were used to study the relationships between fetal and neonatal log body weight in kilograms, and the various cardiometric parameters. We believe that these morphometric data have immediate clinical and surgical applications in the treatment of fetal and neonatal cardiovascular disorders.

Morphometric methods were used to study hearts with perimembranous ventricular septal defects in 22 human fetuses and neonates weighing from one to 3.8 kg (2.221±0.852 kg). All specimens displayed concordant atrioventricular and ventriculoarterial connections, and all had perimembranous ventricular septal defects. A total of 17 interventricular parameters (nine in the right ventricle and eight in the left) were measured in each specimen. The values were compared with patterns of normality established by Rowlatt and her colleagues in hearts from 83 children ranging in age from birth to 15 years. These patterns were found to be less reliable than our own data from fetal and perinatal hearts from children ranging in age from birth to one month. Our morphological data, when appropriately interpreted, have immediate clinical and surgical applications in the treatment of fetal and perinatal cardiovascular disorders.

Microdissection of the oval fossa from its right and left atrial aspects showed that the rim of the fossa was formed from an infolding of the atrial wall, which began between the base of the superior caval vein and the insertion of the right pulmonary vein to the left atrium. Because the rim varied in shape from circular to oval, we used morphometric methods to obtain patterns of normality of the diameters of the oval fossa, oval foramen, and the area of right and left atrial aspects of the septum. These values were found to correlate with log fetal and neonatal weight. Due to technical advances in prenatal diagnosis, these structures can now be examined in fetal life. Therefore, our morphometric data, when appropriately interpreted, have immediate clinical and surgical applications in the treatment of fetal and neonatal cardiovascular disorders.