Gestational age-specific predicted risk of neonatal respiratory distress syndrome using lamellar body count and surfactant-to-albumin ratio in amniotic fluid.
OBJECTIVE
This study was undertaken to study the statistical correlation between lecithin/sphingomylein (L/S) ratio, percent phosphatidylglycerol (%PG), lamellar body count (LBC), and surfactant-to-albumin ratio (TDx-FLM(II)) in amniotic fluid (AF); and derive gestational age-specific (GA) predicted risk of neonatal respiratory distress syndrome (RDS) for LBC and TDx-FLM(II).


METHODS
AF specimens (238) were collected by transabdominal amniocentesis. L/S ratio, %PG, LBC, and TDx-FLM(II) were determined by established procedures. RDS diagnosis was ascertained by a neonatalogist, and statistical analyses were performed with the use of the SPSS software program (SPSS Inc, Chicago, Ill).


RESULTS
Significant correlation was obtained among the 4 variables (L/S ratio, %PG, LBC, and TDx-FLM(II)). Independent linear regression analyses between L/S ratio versus LBC and TDx-FLM(II) provided acceptable correlation. Multiple regression analysis showed a significant (P < .001) contribution from TDx-FLM(II) and GA for predicting the L/S ratio. Receiver operating characteristic curve analysis provided the immature cutoffs (LBC = < 30.0 x 10(3)/microL; TDx-FLM(II) = < 40.0 mg/g). Total accuracy (either positive or negative) for RDS was similar for LBC (75.5%) and TDx-FLM(II) (76.7%).


CONCLUSIONS
LBC and TDx-FLM(II) are equally accurate. GA-specific predicted risk of RDS by both tests significantly eliminated L/S ratio identified false positive cases of fetal lung maturity.
Karcher
Raymond
R
Department of Clinical Pathology, William Beaumont Hospital, Royal Oak, MI, USA.
Sykes
Elizabeth
E
Batton
Daniel
D
Uddin
Zi
Z
Ross
Gary
G
Hockman
Elaine
E
Shade
George H
GH
D000293:Adolescent; D000328:Adult; D000418:Albumins / Q000032:analysis*; D000653:Amniotic Fluid / Q000737:chemistry*; D005325:Fetal Organ Maturity; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D008168:Lung / Q000196:embryology; D008875:Middle Aged; D011663:Pulmonary Surfactants / Q000032:analysis*; D012127:Respiratory Distress Syndrome, Newborn / Q000175:diagnosis / Q000453:epidemiology*; D012307:Risk Factors
D000418:Albumins; D011663:Pulmonary Surfactants