title: The probability of neonatal respiratory distress syndrome as a function of gestational age and lecithin/sphingomyelin ratio.
abstract: We sought to define the risk of neonatal respiratory distress syndrome (RDS) as a function of both lecithin/sphingomyelin (L/S) ratio and gestational age. Amniotic fluid L/S ratio data were collected from consecutive women undergoing amniocentesis for fetal lung maturity at Yale-New Haven Hospital from January 1998 to December 2004. Women were included in the study if they delivered a live-born, singleton, nonanomalous infant within 72 hours of amniocentesis. The probability of RDS was modeled using multivariate logistic regression with L/S ratio and gestational age as predictors. A total of 210 mother-neonate pairs (8 RDS, 202 non-RDS) met criteria for analysis. Both gestational age and L/S ratio were independent predictors of RDS. A probability of RDS of 3% or less was noted at an L/S ratio cutoff of > or = 3.4 at 34 weeks, > or = 2.6 at 36 weeks, > or = 1.6 at 38 weeks, and > or = 1.2 at term. Under 34 weeks of gestation, the prevalence of RDS was so high that a probability of 3% or less was not observed by this model. These data describe a means of stratifying the probability of neonatal RDS using both gestational age and the L/S ratio and may aid in clinical decision making concerning the timing of delivery.
authors.affiliation: Department of Obstetrics, Gynecology & Reproductive Sciences, Yale University School of Medicine, New Haven, Connecticut 06520-8063, USA.
authors.forename: Caryn
authors.initials: C
authors.lastname: St Clair
authors.forename: Errol R
authors.initials: ER
authors.lastname: Norwitz
authors.forename: Karlijn
authors.initials: K
authors.lastname: Woensdregt
authors.forename: Michael
authors.initials: M
authors.lastname: Cackovic
authors.forename: Julia A
authors.initials: JA
authors.lastname: Shaw
authors.forename: Herbert
authors.initials: H
authors.lastname: Malkus
authors.forename: Richard A
authors.initials: RA
authors.lastname: Ehrenkranz
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Illuzzi
mesh_terms: D000653:Amniotic Fluid / Q000737:chemistry*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D054709:Lecithins / Q000032:analysis*; D016015:Logistic Models; D012127:Respiratory Distress Syndrome, Newborn / Q000453:epidemiology*; D018570:Risk Assessment; D013109:Sphingomyelins / Q000032:analysis*
chemical_list: D054709:Lecithins; D013109:Sphingomyelins
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