Objective: To measure fetal lung volume by echo-planar magnetic resonance imaging (MRI).
Methods: Twenty singleton pregnancies were scanned on one occasion each using echo-planar imaging, a form of MRI. Cases of fetal growth restriction and macrosomia were excluded from the study.
Results: Lung volumes increased with gestational age from 21 mL at 23 weeks' gestation to a maximum of 94 mL at term. The relation between lung volume and gestational age was exponential. The ratio of lung volume to total fetal volume decreased with gestational age.
Conclusion: The use of echo-planar imaging allows estimation of normal fetal growth; it has clear applications for the diagnosis of lung hypoplasia and potential use for the study of lung maturity.