The three-vessel and tracheal view of the fetal heart: an in utero sonographic evaluation

OBJECTIVES: To establish a nomogram for fetal cardiac three-vessel view diameter changes during gestation. METHODS: The study is a prospective cross-sectional evaluation of 338 male and female fetuses between 14 and 38 weeks of normal singleton pregnancies. Measurements of fetal pulmonary artery, aorta and superior vena cava diameters, performed on a transverse view of the upper mediastinum were conducted using transvaginal ultrasonography between 14 to 18 weeks and transabdominal after 19 weeks' gestation. RESULTS: Adequate measurements of the three cardiac vessels were obtained in 338 fetuses. The regression equations for vessel diameters modeled as function of gestational age were pulmonary artery diameter (mm) = -2.275 + 0.273 x gestational age (week), aorta diameter (mm) = -1.77 + 0.227 x gestational age (week), and SVC diameter (mm) = -0.98 + 0.142 x gestational age (week). The correlation coefficients between gestational age and the diameter of the vessels were, r = 0.93, r = 0.93 and r = 0.86 for pulmonary artery, aorta and SVC respectively (all found to be highly statistically significant, p < 0.0001). The normal mean and 90% prediction limits were defined. CONCLUSION: Our data present the normal range of fetal heart three-vessel diameters during gestation. They may allow intrauterine assessment of their development and an adjunct in the detection and evaluation of great vessel pathology.