A comparison of three tests for determining fetal pulmonary maturity.
OBJECTIVE
The aim of the study was to determine the sensitivity, specificity and predictive value of two simple and cheap diagnostic tests of fetal pulmonary maturity (FPM) and compare them with the more complex and expensive phospholipid profile (PP), which includes the determination of phosphatidyl glycerol (PG) and the lecithin/sphingomyelin (L/S) ratio.


METHODS
Samples of amniotic fluid were obtained from 70 patients between the 26th and 38th weeks of pregnancy. The PP, shake test and tap test at 2, 5 and 10 min were determined. All patients gave birth within 12 h following these tests and none received corticoids during this period. The neonates were observed for 72 h. The results of the tests were compared with the incidence of neonatal respiratory distress syndrome.


RESULTS
The sensitivity of the shake test was 92% for FPM, as was the sensitivity of PP, while for the tap test at 2, 5 and 10 min it was between 96 and 100%. In terms of specificity, the 5- and 10-min tap test diagnoses were 100% correct for immaturity while all other tests were 60-78% correct. The predictive value for maturity was 100% for the tap test (5 and 10 min), 67% for the 2-min tap test, 64% for PG, 60% for L/S and 56% for the shake test.


CONCLUSIONS
The tap test is a good alternative to other diagnostic methods of FPM. Its use at the bedside, its rapidity and low cost enhance its value.
Rodriguez-Macias
K A
KA
Department of Gynecology and Obstetrics, University Hospital, Clinica San Rafael, Santafe de Bogota, D.C., Colombia.
D000653:Amniotic Fluid / Q000737:chemistry*; D005260:Female; D005325:Fetal Organ Maturity; D006801:Humans; D008168:Lung / Q000196:embryology*; D010743:Phospholipids / Q000032:analysis*; D011237:Predictive Value of Tests; D011247:Pregnancy; D012680:Sensitivity and Specificity
D010743:Phospholipids