title: Correlation of ultrasonic epiphyseal centers and the lecithin: sphingomyelin ratio.
abstract: Ossification centers about the fetal knee were identified and measured by ultrasound in 133 nondiabetic patients who underwent amniocentesis for determination of the amniotic fluid lecithin:sphingomyelin ratio (L:S ratio) between 28 and 42 weeks' gestation. A distal femoral epiphysis measuring greater than or equal to 5 mm and a proximal tibial epiphysis measuring 3 mm or greater was seen at 34 to 35 weeks' gestation. A mature lecithin: sphingomyelin ratio (lecithin: sphingomyelin greater than or equal to 2.0) was present with 66, 94, and 100% of proximal tibial epiphysis measuring 0 to 2, 3 to 4, and 5 to 7 mm, respectively. A mature lecithin: sphingomyelin ratio was present with 39, 76, and 95% of distal femoral epiphysis measuring 0 to 2, 3 to 4, and 5 to 7 mm, respectively. These results suggest that in nondiabetic patients, the ossification centers about the fetal knee as measured by ultrasound correlate well with amniotic fluid lecithin: sphingomyelin ratio.
mesh_terms: D000649:Amniocentesis; D000653:Amniotic Fluid / Q000032:analysis*; D004838:Epiphyses / Q000473:pathology*; D005260:Female; D005317:Fetal Growth Retardation / Q000175:diagnosis*; D005325:Fetal Organ Maturity; D006801:Humans; D008168:Lung / Q000196:embryology; D009999:Ossification, Heterotopic / Q000175:diagnosis; D010713:Phosphatidylcholines / Q000032:analysis*; D010715:Phosphatidylglycerols / Q000032:analysis; D011247:Pregnancy; D013109:Sphingomyelins / Q000032:analysis*; D013977:Tibia / Q000473:pathology; D014463:Ultrasonography
chemical_list: D010713:Phosphatidylcholines; D010715:Phosphatidylglycerols; D013109:Sphingomyelins; C017463:lecithins, disaturated