title: The relationship of placental grade by ultrasound to markers of fetal lung maturity.
abstract: Seventy-two amniocenteses with concurrent placental grading by ultrasound were performed during 66 pregnancies. No relationship was observed between placental grade and the mean ratio of lecithin to sphingomyelin (L/S) or the phosphatidylglycerol concentration. Both placental grade and fetal lung maturity were interrelated by the independent variable of gestational age. The latter may explain the trend observed between a mature L/S ratio and the placental grade. Grade 3 placentas were present in only 20% of patients studied at 37 weeks of gestation or later (12 of 61 patients), and in every instance a Grade 3 placenta was associated with an absence of neonatal respiratory distress.
mesh_terms: D000649:Amniocentesis; D005260:Female; D005325:Fetal Organ Maturity; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D008168:Lung / Q000196:embryology*; D010713:Phosphatidylcholines / Q000032:analysis; D010920:Placenta / Q000473:pathology*; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods; D012127:Respiratory Distress Syndrome, Newborn / Q000175:diagnosis*; D013109:Sphingomyelins / Q000032:analysis; D014463:Ultrasonography
chemical_list: D010713:Phosphatidylcholines; D013109:Sphingomyelins