title: Lecithin/sphingomyelin ratio and lamellar body count for fetal lung maturity: a meta-analysis.
abstract: OBJECTIVE
  To determine and compare the diagnostic accuracy of the lecithin/sphingomyelin (L/S) ratio and lamellar body count (LBC) in the prediction of neonatal respiratory distress syndrome (RDS).
  
  
  METHODS
  A systematic review was performed to identify studies comparing either the L/S ratio or the LBC with the occurrence of RDS published between January 1999 and February 2009. Two independent reviewers performed study selection and data extraction. For each study sensitivity and specificity were calculated. Summary receiver-operating characteristics (ROC) curves, assessing the diagnostic performance of both tests, were constructed. A subgroup analysis was performed to estimate the sensitivity and specificity of the various cut-off values.
  
  
  RESULTS
  13 studies were included. The ROC curves of the collected data illustrate that the LBC and L/S ratio perform equally well in the prediction of RDS. Comparison of the two summary ROC curves of each test indicates that the diagnostic performance of LBC might even have a slight advantage over L/S ratio. Due to the wide cut-off range it was not possible to define specific cut-off values with the best accuracy.
  
  
  CONCLUSIONS
  We recommend replacing the L/S ratio as gold standard with the lamellar body count since the LBC is easy to perform, rapid, inexpensive, and available to all hospitals 24h per day.
authors.affiliation: Faculty of Medicine, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Anouk E
authors.initials: AE
authors.lastname: Besnard
authors.forename: Soetinah A M
authors.initials: SA
authors.lastname: Wirjosoekarto
authors.forename: Kimiko A
authors.initials: KA
authors.lastname: Broeze
authors.forename: Brent C
authors.initials: BC
authors.lastname: Opmeer
authors.forename: Ben Willem J
authors.initials: BW
authors.lastname: Mol
mesh_terms: D000653:Amniotic Fluid / Q000166:cytology*; D005260:Female; D005325:Fetal Organ Maturity; D006801:Humans; D054709:Lecithins / Q000378:metabolism; D008168:Lung / Q000196:embryology*; D011237:Predictive Value of Tests; D011247:Pregnancy; D012127:Respiratory Distress Syndrome, Newborn / Q000378:metabolism; D013109:Sphingomyelins / Q000378:metabolism
chemical_list: D054709:Lecithins; D013109:Sphingomyelins
keywords: Fetal lung maturity; Lamellar body count; Lecithin/sphingomyelin ratio; Neonatal respiratory distress syndrome