Sbarra A J, Cetrulo C L, Selvaraj R J, Spinosa D, Herschel M J, Blake G D, Delise C M, Kennedy J L, Mitchell G W
J Reprod Med. 1982 Jan;27(1):34-8.
Optical density readings of amniotic fluids of 0.15 or greater at 650 nm have been noted to correlate with fetal pulmonary maturity. The amniotic fluid absorbance has been shown to be due not only to lecithin and sphingomyelin but also to other surfactants, including phosphatidyl glycerol and inositol. The addition of lecithin and sphingomyelin to previously centrifuged amniotic fluid (i.e., optical) density less than 0.001: L/S ratio, nondetectable) results in an increase in absorbance. At any simulated L/S ratio, the addition of phosphatidyl glycerol and/or phosphatidyl inositol results in a further increase in optical density. It is suggested that optical density readings represent more closely the surfactant composition of amniotic fluid than L/S ratios; therefore, it appears that optical density measurements are a better predictor of fetal pulmonary development than are L/S ratios.
已注意到，羊水在650纳米处的光密度读数为0.15或更高与胎儿肺成熟度相关。羊水吸光度已表明不仅归因于卵磷脂和鞘磷脂，还归因于其他表面活性剂，包括磷脂酰甘油和肌醇。向先前离心的羊水（即光密度小于0.001：L/S比值，无法检测到）中添加卵磷脂和鞘磷脂会导致吸光度增加。在任何模拟的L/S比值下，添加磷脂酰甘油和/或磷脂酰肌醇会导致光密度进一步增加。有人提出，光密度读数比L/S比值更能准确反映羊水的表面活性剂组成；因此，光密度测量似乎比L/S比值更能预测胎儿肺部发育。
