Fetal thoracic circumference: a prospective cross-sectional study with real-time ultrasound.

We report a prospective cross-sectional study of ultrasound fetal chest growth during normal pregnancy. The fetal chest circumference was measured in 100 normal pregnancies from 13 to 41 weeks' gestation. Nomograms of chest circumference versus gestational age and femur length were constructed. Data from 18 cases at risk for pulmonary hypoplasia indicated that the fetal chest circumference measurement may be useful in the antenatal prediction of lethal or clinically severe pulmonary hypoplasia.