Noninvasive fetal lung maturity prediction based on ultrasonic gray level histogram width.

The aim of this work was to noninvasively predict fetal lung immaturity with the ultrasonic gray level histogram width (GLHW), a form of clinical tissue characterization. The study included 22 fetuses in which infant respiratory distress syndrome (IRDS) developed post-delivery, and 25 fetuses without IRDS development. Independent receiver operating characteristic (ROC) analysis of fetal lung-to-liver GLHW ratios, fetal weights, gestational ages and the product of GLHW ratios by gestational ages for this cohort indicated that optimal thresholds for these parameters to differentiate immature from mature were 0.94, 1.750 g, 31 weeks and 29, respectively. With the optimal decision threshold of 0.94, the GLHW ratio provided sensitivity and specificity of 0.86 and 0.72, respectively. The corresponding values for gestational age were 0.77 and 0.68, 0.77 and 0.60 for fetal weight versus 0.96 and 0.72 for the product of GLHW ratio by fetal age, which was comparable with invasive amniotic fluid tests. The areas under the ROC curve for these parameters were 0.82, 0.82, 0.70 and 0.91. We found that GLHW is a noninvasive, stable and reliable measure of fetal lung maturity using commercial scanners.