Three-dimensional sonographic volume measurement of the fetal lung

Aim: The objective of this longitudinal study was to evaluate the growth of the fetal lung in normal pregnancies, using 3-D ultrasound. Methods: 3-D sonographic examinations were performed on 14 appropriate-for-gestational-age fetuses. Fetal lung volumes (left, right, and total lung volumes) were measured every 2-3 weeks from 20 weeks of gestational age until delivery. The common multiplanar technique was used to calculate fetal lung volume. Results: Curvilinear relationships were found between the gestational age and left (R-2 = 86.9%, P < 0.0001), right (R-2 = 83.9%, P < 0.0001) and total (R-2 = 83.8%, P < 0.0001) lung volumes. The data described in this study were fairly comparable with previous data from autopsy series. However, there were big differences for predicted values of the fetal total lung volumes using 3-D ultrasound among the present study and previous investigations. Conclusions: Our findings suggest that the standard curve for fetal lung volume using 3-D ultrasound provides a role for evaluating the normal lung growth in the fetus. However, we do cast doubt on the reliability and reproducibility of fetal lung volume measurements using 3-D ultrasound. Moreover, the data and its interpretation in our study should be taken with some degree of caution because of the small number of subjects studied. Further studies involving a larger sample size would be needed to confirm these findings.