External diameters of the pulmonary arteries in human foetuses: an anatomical, digital and statistical study

This study defines the growth patterns for the external diameters of the pulmonary arteries in human foetuses, including relationships with sex, side of body (right-left) and foetal age. Using anatomical dissection, digital-image analysis (system of Leica Q Win Pro 16) and statistical analysis (ANOVA, regression analysis), a range of external diameters for the right and left pulmonary arteries in 128 spontaneously aborted human foetuses aged 15-34 weeks was examined. No significant gender differences were found (p > 0.05). In the examined age range the values of the external diameter of the right pulmonary artery ranged from 0.97 +/- 0.24 to 2.95 +/- 0.89 mm, according to the linear function y = -0.7753 + 0.1148 x +/- 0.4580 (r = 0.83; p < 0.001). The values of the external diameter of the left pulmonary artery ranged from 0.88 +/- 0.25 to 2.63 +/- 0.80 mm, in accordance with the linear relationship y = -0.6228 + 0.1007 x +/- 0.4280 (r = 0.81; p < 0.001). The external diameters of the right pulmonary artery were greater than those of the left pulmonary artery (p < 0.001). Parallel to the increase in the values of the external diameters of both the pulmonary arteries, the pulmonary artery-to-ascending aorta diameter ratio (the relative diameter of the pulmonary artery) decreased with advanced foetal age from 0.46 +/- 0.10 to 0.43 +/- 0.13 for the right pulmonary artery, and from 0.43 +/- 0.10 to 0.39 +/- 0.12 for the left one. The growth curves generated may be useful as reference data for foetal diagnosis.