Noninvasive prediction of hyaline membrane disease: an optimized classification of sonographic placental maturation

Accurate prediction of fetal pulmonary maturity by means of a less invasive procedure than amniocentesis would be desirable. Sonographic diagnosis of a Grade III placenta has been reported to be an excellent predictor of fetal lung maturity. The standard classification of placental grading assigns grade according to the most advanced portion of the placenta. Using this classification, we studied 230 patients. In 80 pregnancies with Grade III placenta, three of the neonates developed respiratory distress syndrome. With reclassification of the placentas as immature, (no Grade III areas), intermediate, (only a portion of the placenta being Grade III), or mature, (Grade III placenta throughout), it was found that no neonatal hyaline membrane disease occurred in the 41 pregnancies with mature placentas, whereas 12% of the neonates in the immature group and 8% in the intermediate group developed hyaline membrane disease. These findings suggest that when sonographic examination of the placenta shows both Grade III and non-Grade III sections, there is still a risk for an immature amniotic fluid lecithin/sphingomyelin ratio and neonatal hyaline membrane disease. The placentas should be considered mature only when Grade III changes are present in all sections examined by ultrasound.