Prediction of lethal pulmonary hypoplasia among high-risk fetuses via 2D and 3D ultrasonography.

OBJECTIVE: To compare accuracy between 3D and 2D ultrasonography for predicting lethal pulmonary hypoplasia (LPH) among high-risk fetuses.

METHODS: In a cross-sectional prospective study at a fetal medicine referral center in Brazil, bilateral fetal lung scans were evaluated for 54 fetuses with suspected LPH between May 2008 and June 2011. Measurements for predicting LPH were ultrasonographic fetal lung volume/estimated fetal weight ratio (US-FLW), observed/expected thoracic circumference (o/e-TC), observed/expected thoracic circumference/abdominal circumference (o/e-TC/AC), observed/expected thoracic area/heart area (o/e-TA/HA), observed/expected amniotic fluid index (o/e-AFI), and observed/expected total fetal lung volume (o/e-Tot-FLV). To evaluate accuracy in predicting LPH, receiver operating characteristic (ROC) curves were calculated, and areas under the curves (AUCs) were compared. The intraclass correlation coefficient (ICC) was used to assess 3D lung volume reproducibility.

RESULTS: Data were compared for 47 newborns, of whom 34 had LPH (perinatal mortality 74.5%). The AUCs for predicting LPH were 0.93, 0.69, 0.55, 0.46, 0.71, and 0.86 for US-FLW, o/e-TC, o/e-TC/AC, o/e-TA/HA, o/e-AFI, and o/e-Tot-FLV, respectively. No significant intraobserver difference was observed in measurements of the right (ICC, 0.973; P < 0.0001) or left (ICC, 0.950; P < 0.0001) lung volumes.

CONCLUSION: Among high-risk fetuses, US-FLW by 2D/3D and o/e-Tot-FLV by 3D ultrasonography were more accurate than 2D parameters for predicting LPH.