Study on a new index of fetal respiratory function: a novel optical analysis of the amniotic fluid by the vacuum-dried infrared attenuated total reflection (ATR) method.
For the purpose of detecting fetal pulmonary maturity with real-time convenience but reliable accuracy, infrared spectrophotometry of amniotic fluid lipids was introduced using our newly developed optical device. The peak areas at the wave number of 1740 cm-1 on the infrared spectra (called "PA1740") were measured in 29 specimens sampled from 29 pregnant women, and compared with the Lecithin/Sphingomyelin (L/S) ratio of the same samples. Statistical analysis revealed that the PA1740 was almost as reliable as the L/S ratio, and these indices illustrated pulmonary immaturity in cases with a PA1740 less than 0.9 and an L/S ratio less than 2.0. PA1740 is absolutely independent of the effect on the concentration of lecithin in the amniotic fluid because of a combination of the vacuum-drying process and the absorbance correction, and can be completed in less than 20 minutes from sampling of the amniotic fluid by a very simple manipulation. In conclusion, the new index, PA1740, will be a more practical method for prediction of the fetal pulmonary maturity than methods such as the well known L/S ratio.
Kobayashi
H
H
Tateyama Air Medical Service Unit, Japan Maritime Self-Defense Force, Department of Perinatal and Maternal Medicine, National Defense Medical College, Saitama.
Kobayashi
M
M
Arai
T
T
Kikuchi
M
M
Okino
H
H
D000653:Amniotic Fluid / Q000737:chemistry*; D005260:Female; D005325:Fetal Organ Maturity; D005333:Fetus / Q000502:physiology*; D005544:Forecasting; D006801:Humans; D007231:Infant, Newborn; D007259:Infrared Rays; D008168:Lung / Q000196:embryology; D010713:Phosphatidylcholines / Q000032:analysis; D011247:Pregnancy; D012119:Respiration; D012127:Respiratory Distress Syndrome, Newborn / Q000175:diagnosis; D012129:Respiratory Function Tests; D012680:Sensitivity and Specificity; D013053:Spectrophotometry / Q000379:methods*
D010713:Phosphatidylcholines