ABSTRACT
ObjectiveTo evaluate the application of chest-abdomen longitudinal diameter ratio,total lung area and lung longitudinal diameter in different gestational ages by two-dimensional ultrasonography.MethodsFive hundred and ninty-two fetus of normal singleton pregnancy between 18 and 40 weeks were ultrasonic scanned by standard 4-chamber view and fetus torso coronal section.The heart area,thoracic area,bilateral lungs pointed to the corresponding diaphragmatic dome gallery on the top of the vertical distance,diaphragmatic dome iterated top to the bottom of the fetal bladder distance were measured respectively.Related regression analysis was done on fitting total lung area and longitudinal diameter with pregnant increasing.ResultsA normal pregnancy fetal total lung area and lung longitudinal diameter were increased as long as the gestational age.The best-fit regression equations of total lung area was:Y =0.83 X +13.894,R2 =0.914;Lung longitudinal diameter was:Y =0.669 X + 3.124,R2 =0.892.Chest-abdomen longitudinal diameter ratio from 18 to 40 weeks gestation was in constant range:0.44 - 0.59.Conclusions Chest-abdomen longitudinal diameter ratio from 18 to 40 weeks gestation is in constant range.The normal pregnancy fetal total lung area and lung longitudinal diameter were increased as long as the gestational age.These parameters may be useful for the prenatal assessment of lung development.