Worthington D, Smith B T
Obstet Gynecol. 1978 Nov;52(5):552-4.
Simultaneous sampling of amniotic fluid from two sites within the amniotic cavity proximal and distal to the fetal mouth was performed. The lecithin-sphingomyelin (L/S) ratio of amniotic fluid obtained close to the fetal mouth was usually higher than that of amniotic fluid obtained from a site distal to the fetal mouth (20 of 26 cases). Differences of up to 0.7 in the two L/S ratios were measured. This suggested that pooling of amniotic fluid phospholipids occurred and in cases of borderline pulmonary maturity the site of amniocentesis may have influenced the predictive value of the L/S ratio.
在羊膜腔内胎儿口腔近端和远端的两个部位同时采集羊水样本。靠近胎儿口腔采集的羊水卵磷脂 - 鞘磷脂（L/S）比值通常高于从胎儿口腔远端部位采集的羊水（26例中有20例）。两个L/S比值的差异测量高达0.7。这表明羊水磷脂发生了聚集，在肺成熟临界情况下，羊膜穿刺部位可能影响了L/S比值的预测价值。
