title: Biparietal diameter as a predictor of fetal lung maturity.
abstract: A correlation has been established between fetal biparietal diameter (BPD), amniotic fluid lecithin/sphingomyelin (L/S) ratio and optical density at 650 nm (O.D. 650). We have noted that if the BPD is greater than 9.2 cm, the L/S ratio and O.D. 650 will be greater than 2.0 and 0.15, respectively, in 90% of cases. We reviewed the literature on the complication rate of third-trimester amniocentesis under ultrasonic guidance and concluded that in the absence of good dating, a reliably obtained BPD greater than 9.2 cm indicates fetal lung maturity in cases where amniotic fluid studies cannot be performed.
mesh_terms: D000649:Amniocentesis; D000653:Amniotic Fluid / Q000032:analysis; D002508:Cephalometry; D005260:Female; D005325:Fetal Organ Maturity; D005333:Fetus / Q000033:anatomy & histology; D006801:Humans; D008168:Lung / Q000196:embryology*; D010713:Phosphatidylcholines / Q000032:analysis; D011247:Pregnancy; D013109:Sphingomyelins / Q000032:analysis; D014463:Ultrasonography
chemical_list: D010713:Phosphatidylcholines; D013109:Sphingomyelins