A modified activated partial thromboplastin time with the use of amniotic fluid. Preliminary report of a new technique for detection of fetal lung maturity.
The need for a simple, accurate, rapidly performed fetal lung maturity test remains unfilled despite the large number of methods available. In a preliminary prospective study, the amniotic fluid activated partial thromboplastin time (PTT) appeared to be encouraging. The false mature rate in an at-risk patient population was 0.80%, and the false immature rate was 61%. The false mature rates for the lecitin/sphingomyelin ratio and absorbance 650 in the same patients were 0% and 0.63%, respectively, whereas the false immature rates were 81.8% and 91.3%. Since both the amniotic fluid activated PTT and absorbance 650 can be readily performed in the smallest hospital, the accuracy of the combination was explored. Combining the amniotic fluid activated PTT with a mature absorbance 650 reduced the false immature rate to 30.7%. Th amniotic fluid activated PTT is a rapid, accurate, economical test that is unaffected by gross blood or meconium contaminants.
D000653:Amniotic Fluid / Q000502:physiology*; D001780:Blood Coagulation Tests; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D005325:Fetal Organ Maturity; D005865:Gestational Age; D006801:Humans; D008168:Lung / Q000196:embryology*; D008722:Methods; D010314:Partial Thromboplastin Time; D011247:Pregnancy