Phosphatidylglycerol in amniotic fluid. Comparison of an "ultrasensitive" immunologic assay with TLC and enzymatic assay.
Phosphatidylglycerol (PG) in amniotic fluid is recognized as a good indicator of fetal lung maturity and is unaffected by moderate amounts of blood or meconium contamination. A rapid immunologic agglutination assay, Ultrasensitive AmnioStat-FLM (FLM), was compared with two-dimensional thin-layer chromatography (TLC) and an enzymic, colorimetric procedure (E-PG). Eighty amniotic fluid specimens were analyzed. FLM results were reported as high (H), intermediate (I), or low positive (L). TLC was compared with FLM:H (n = 27), mean 0.14 (fraction of total phospholipids); I (n = 7), mean 0.11; L (n = 9), mean 0.03; negative results had no detectable PG by TLC. In 33 cases E-PG was compared with FLM:H (n = 9), mean 7.0 mumol/L; I (n = 5), mean 8.1 mumol/L; L (n = 3), mean 3.0 mumol/L; negative (n = 16), mean 3.2 mumol/L. Records were reviewed in 70 cases. Thirty cases were excluded: sample to delivery time was greater than 72 hours; steroids were given or sepsis was documented. Fetal lung immaturity was clinically present in six cases: respiratory distress syndrome in three cases and transient tachypnea of the newborn (TTN) in three cases. One false positive result was identified (TTN, FLM:H). FLM sensitivity for fetal lung maturity was 85.3%, specificity was 83.3%, and the positive predictive value for fetal lung maturity was 96.7%. FLM is a fast, reliable indicator of fetal lung maturity.
Eisenbrey
A B
AB
Department of Clinical Pathology, William Beaumont Hospital, Royal Oak, Michigan 48072.
Epstein
E
E
Zak
B
B
McEnroe
R J
RJ
Artiss
J D
JD
Kiechle
F L
FL
D000372:Agglutination Tests / Q000592:standards; D000653:Amniotic Fluid / Q000032:analysis*; D002855:Chromatography, Thin Layer / Q000592:standards; D003124:Colorimetry; D005314:Embryonic and Fetal Development; D004798:Enzymes; D005260:Female; D006801:Humans; D008168:Lung / Q000196:embryology; D009994:Osmolar Concentration; D010715:Phosphatidylglycerols / Q000032:analysis*; D011247:Pregnancy; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity
D004798:Enzymes; D010715:Phosphatidylglycerols; D011933:Reagent Kits, Diagnostic