Influence of gestational age on prediction of fetal lung maturity by fluorescence polarization of amniotic fluid.
Compared are the amniotic fluid fluorescence polarization values and the neonatal outcomes of 201 pregnant women who delivered from 28 through 37 weeks of gestation within 48 hours of the fluorescence polarization determinations. Thirty-five neonates developed hyaline membrane disease. The corresponding fluorescence polarization values ranged from 0.275 to 0.391. Eight of those 35 tests results were less than 0.325. The predictiveness of the method was studied using different threshold fluorescence polarization values. At the authors' own threshold of less than or equal to 0.325, the overall predictive value was as follows: false mature predictions: 6.2%, false immature predictions: 62.5%, sensitivity: 77.1%, and specificity: 72.8%. However, the false mature prediction rate was 21 to 40% from week 28 through week 33 versus 3.4 to 5.8% from week 34 through week 37, depending on the selected cutoff fluorescence polarization value. The sensitivity and specificity before, at, or after week 34 were significantly different at all tested fluorescence polarization values (P less than .05 to P less than .01) with the exception of the sensitivity at 0.310 and at 0.316 (P = .057). Caution is advised against relying on the fluorescence polarization method to predict fetal lung maturity at least before 34 weeks of gestation.
D000653:Amniotic Fluid / Q000032:analysis*; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D005325:Fetal Organ Maturity; D005454:Fluorescence Polarization; D005865:Gestational Age; D006801:Humans; D006819:Hyaline Membrane Disease / Q000175:diagnosis; D007231:Infant, Newborn; D008168:Lung / Q000196:embryology*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000503:physiopathology; D011296:Prenatal Diagnosis; D012127:Respiratory Distress Syndrome, Newborn / Q000175:diagnosis